我想使用 for 循环来获取 jquery 中复选框和文本框的 id

您可以使用名称选择器选中所有复选框，因为它们都具有相同的名称，然后您可以在与复选框相同的span中找到技术输入元素

 $(document).ready(function() {
   $('input[name="technology"]').click(function() {
     var $input = $(this).closest('span').find('input[name="tech"]');
     $input.prop('disabled', !this.checked);
     if (this.checked) {
       $input.focus();
     }
   });
 });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form method="POST" action="<?php echo htmlspecialchars($_SERVER[" PHP_SELF "]);?>" id="myform1" novalidate="novalidate">
  <table cellspacing="0" cellpadding="0" border="0" align="center" width="100%" style="padding-left:10px; vertical-align:top;">
    <!--<tr>
                <td class="contact-form-heading" colspan="3">Hire Our 
Professionals</td>
              </tr>-->
    <tr id="response">
      <td colspan="3"></td>
    </tr>
    <tr>
      <td width="25%" class="contact-form">Name</td>
      <td width="5%" class="contact-form">:</td>
      <td width="70%" class="contact-text-form">
        <input type="text" class="contact-form-filds" name="username" id="username">
      </td>
    </tr>
    <tr>
      <td class="contact-form">E-mail Address</td>
      <td class="contact-form">:</td>
      <td width="70%" class="contact-text-form">
        <input type="email" class="contact-form-filds" name="email">
        </span>
      </td>
    </tr>
    <tr>
      <td class="contact-form">Phone Number</td>
      <td class="contact-form">:</td>
      <td width="70%" class="contact-text-form">
        <input type="text" class="contact-form-filds" name="phoneno" id="phoneno">
      </td>
    </tr>
    <tr>
      <td valign="top" class="contact-form">Country</td>
      <td valign="top" class="contact-form">:</td>
      <td width="70%" class="contact-text-form">
        <select style="height:30px; width:325px; border-radius:9px;" class="box" name="country" id="country">
          <option value="">--Select Country--</option>
          <option value="AF">Afghanistan</option>
          <option value="AL">Albania</option>
          <option value="AS">American Samoa</option>
          <option value="AD">Andorra</option>
          <option value="AO">Angola</option>
          <option value="AI">Anguilla</option>
          <option value="AQ">Antarctica</option>
          <option value="AG">Antigua and Barbuda</option>
          <option value="AR">Argentina</option>
          <option value="AM">Armenia</option>
          <option value="AW">Aruba</option>
          <option value="AU">Australia</option>
          <option value="AT">Austria</option>
          <option value="AZ">Azerbaijan</option>
          <option value="BS">Bahamas</option>
          <option value="BH">Bahrain</option>
          <option value="BD">Bangladesh</option>
          <option value="BB">Barbados</option>
          <option value="BY">Belarus</option>
          <option value="BE">Belgium</option>
          <option value="BZ">Belize</option>
          <option value="BJ">Benin</option>
          <option value="BM">Bermuda</option>
          <option value="BT">Bhutan</option>
          <option value="BO">Bolivia</option>
          <option value="BA">Bosnia and Herzegowina</option>
          <option value="BW">Botswana</option>
          <option value="BV">Bouvet Island</option>
          <option value="BR">Brazil</option>
          <option value="IO">British Indian Ocean Territory</option>
          <option value="BN">Brunei Darussalam</option>
          <option value="BG">Bulgaria</option>
          <option value="BF">Burkina Faso</option>
          <option value="BI">Burundi</option>
          <option value="KH">Cambodia</option>
          <option value="CM">Cameroon</option>
          <option value="CA">Canada</option>
          <option value="CV">Cape Verde</option>
          <option value="KY">Cayman Islands</option>
          <option value="CF">Central African Republic</option>
          <option value="TD">Chad</option>
          <option value="CL">Chile</option>
          <option value="CN">China</option>
          <option value="CX">Christmas Island</option>
          <option value="CC">Cocos (Keeling) Islands</option>
          <option value="CO">Colombia</option>
          <option value="KM">Comoros</option>
          <option value="CG">Congo</option>
          <option value="CK">Cook Islands</option>
          <option value="CR">Costa Rica</option>
          <option value="CI">Cote D Ivoire</option>
          <option value="HR">Croatia</option>
          <option value="CU">Cuba</option>
          <option value="CY">Cyprus</option>
          <option value="CZ">Czech Republic</option>
          <option value="DK">Denmark</option>
          <option value="DJ">Djibouti</option>
          <option value="DM">Dominica</option>
          <option value="DO">Dominican Republic</option>
          <option value="TP">East Timor</option>
          <option value="EC">Ecuador</option>
          <option value="EG">Egypt</option>
          <option value="SV">El Salvador</option>
          <option value="GQ">Equatorial Guinea</option>
          <option value="ER">Eritrea</option>
          <option value="EE">Estonia</option>
          <option value="ET">Ethiopia</option>
          <option value="FK">Falkland Islands (Malvinas)</option>
          <option value="FO">Faroe Islands</option>
          <option value="FJ">Fiji</option>
          <option value="FI">Finland</option>
          <option value="FR">France</option>
          <option value="FX">France, Metropolitan</option>
          <option value="GF">French Guiana</option>
          <option value="PF">French Polynesia</option>
          <option value="TF">French Southern Territories</option>
          <option value="GA">Gabon</option>
          <option value="GM">Gambia</option>
          <option value="GE">Georgia</option>
          <option value="DE">Germany</option>
          <option value="GH">Ghana</option>
          <option value="GI">Gibraltar</option>
          <option value="GR">Greece</option>
          <option value="GL">Greenland</option>
          <option value="GD">Grenada</option>
          <option value="GP">Guadeloupe</option>
          <option value="GU">Guam</option>
          <option value="GT">Guatemala</option>
          <option value="GN">Guinea</option>
          <option value="GW">Guinea-bissau</option>
          <option value="GY">Guyana</option>
          <option value="HT">Haiti</option>
          <option value="HM">Heard and Mc Donald Islands</option>
          <option value="HN">Honduras</option>
          <option value="HK">Hong Kong</option>
          <option value="HU">Hungary</option>
          <option value="IS">Iceland</option>
          <option value="IN">India</option>
          <option value="ID">Indonesia</option>
          <option value="IR">Iran (Islamic Republic of)</option>
          <option value="IQ">Iraq</option>
          <option value="IE">Ireland</option>
          <option value="IL">Israel</option>
          <option value="IT">Italy</option>
          <option value="JM">Jamaica</option>
          <option value="JP">Japan</option>
          <option value="JO">Jordan</option>
          <option value="KZ">Kazakhstan</option>
          <option value="KE">Kenya</option>
          <option value="KI">Kiribati</option>
          <option value="KP">Korea, Democratic People Republic of</option>
          <option value="KR">Korea, Republic of</option>
          <option value="KW">Kuwait</option>
          <option value="KG">Kyrgyzstan</option>
          <option value="LA">Lao People Democratic Republic</option>
          <option value="LV">Latvia</option>
          <option value="LB">Lebanon</option>
          <option value="LS">Lesotho</option>
          <option value="LR">Liberia</option>
          <option value="LY">Libyan Arab Jamahiriya</option>
          <option value="LI">Liechtenstein</option>
          <option value="LT">Lithuania</option>
          <option value="LU">Luxembourg</option>
          <option value="MO">Macau</option>
          <option value="MK">Macedonia, The Former Yugoslav Republic of</option>
          <option value="MG">Madagascar</option>
          <option value="MW">Malawi</option>
          <option value="MY">Malaysia</option>
          <option value="MV">Maldives</option>
          <option value="ML">Mali</option>
          <option value="MT">Malta</option>
          <option value="MH">Marshall Islands</option>
          <option value="MQ">Martinique</option>
          <option value="MR">Mauritania</option>
          <option value="MU">Mauritius</option>
          <option value="YT">Mayotte</option>
          <option value="MX">Mexico</option>
          <option value="FM">Micronesia, Federated States of</option>
          <option value="MD">Moldova, Republic of</option>
          <option value="MC">Monaco</option>
          <option value="MN">Mongolia</option>
          <option value="MS">Montserrat</option>
          <option value="MA">Morocco</option>
          <option value="MZ">Mozambique</option>
          <option value="MM">Myanmar</option>
          <option value="NA">Namibia</option>
          <option value="NR">Nauru</option>
          <option value="NP">Nepal</option>
          <option value="NL">Netherlands</option>
          <option value="AN">Netherlands Antilles</option>
          <option value="NC">New Caledonia</option>
          <option value="NZ">New Zealand</option>
          <option value="NI">Nicaragua</option>
          <option value="NE">Niger</option>
          <option value="NG">Nigeria</option>
          <option value="NU">Niue</option>
          <option value="NF">Norfolk Island</option>
          <option value="MP">Northern Mariana Islands</option>
          <option value="NO">Norway</option>
          <option value="OM">Oman</option>
          <option value="PK">Pakistan</option>
          <option value="PW">Palau</option>
          <option value="PA">Panama</option>
          <option value="PG">Papua New Guinea</option>
          <option value="PY">Paraguay</option>
          <option value="PE">Peru</option>
          <option value="PH">Philippines</option>
          <option value="PN">Pitcairn</option>
          <option value="PL">Poland</option>
          <option value="PT">Portugal</option>
          <option value="PR">Puerto Rico</option>
          <option value="QA">Qatar</option>
          <option value="RE">Reunion</option>
          <option value="RO">Romania</option>
          <option value="RU">Russian Federation</option>
          <option value="RW">Rwanda</option>
          <option value="KN">Saint Kitts and Nevis</option>
          <option value="LC">Saint Lucia</option>
          <option value="VC">Saint Vincent and the Grenadines</option>
          <option value="WS">Samoa</option>
          <option value="SM">San Marino</option>
          <option value="ST">Sao Tome and Principe</option>
          <option value="SA">Saudi Arabia</option>
          <option value="SN">Senegal</option>
          <option value="SC">Seychelles</option>
          <option value="SL">Sierra Leone</option>
          <option value="SG">Singapore</option>
          <option value="SK">Slovakia (Slovak Republic)</option>
          <option value="SI">Slovenia</option>
          <option value="SB">Solomon Islands</option>
          <option value="SO">Somalia</option>
          <option value="ZA">South Africa</option>
          <option value="GS">South Georgia and the South Sandwich Islands</option>
          <option value="ES">Spain</option>
          <option value="LK">Sri Lanka</option>
          <option value="SH">St. Helena</option>
          <option value="PM">St. Pierre and Miquelon</option>
          <option value="SD">Sudan</option>
          <option value="SR">Suriname</option>
          <option value="SJ">Svalbard and Jan Mayen Islands</option>
          <option value="SZ">Swaziland</option>
          <option value="SE">Sweden</option>
          <option value="CH">Switzerland</option>
          <option value="SY">Syrian Arab Republic</option>
          <option value="TW">Taiwan</option>
          <option value="TJ">Tajikistan</option>
          <option value="TZ">Tanzania, United Republic of</option>
          <option value="TH">Thailand</option>
          <option value="TG">Togo</option>
          <option value="TK">Tokelau</option>
          <option value="TO">Tonga</option>
          <option value="TT">Trinidad and Tobago</option>
          <option value="TN">Tunisia</option>
          <option value="TR">Turkey</option>
          <option value="TM">Turkmenistan</option>
          <option value="TC">Turks and Caicos Islands</option>
          <option value="TV">Tuvalu</option>
          <option value="UG">Uganda</option>
          <option value="UA">Ukraine</option>
          <option value="AE">United Arab Emirates</option>
          <option value="UK">United Kingdom</option>
          <option selected="selected" value="US">United States</option>
          <option value="UM">United States Minor Outlying Islands</option>
          <option value="UY">Uruguay</option>
          <option value="UZ">Uzbekistan</option>
          <option value="VU">Vanuatu</option>
          <option value="VA">Vatican City State (Holy See)</option>
          <option value="VE">Venezuela</option>
          <option value="VN">Viet Nam</option>
          <option value="VG">Virgin Islands (British)</option>
          <option value="VI">Virgin Islands (U.S.)</option>
          <option value="WF">Wallis and Futuna Islands</option>
          <option value="EH">Western Sahara</option>
          <option value="YE">Yemen</option>
          <option value="YU">Yugoslavia</option>
          <option value="ZR">Zaire</option>
          <option value="ZM">Zambia</option>
          <option value="ZW">Zimbabwe</option>
        </select>
      </td>
    </tr>
    <tr>
      <td valign="top" class="contact-form">Company</td>
      <td valign="top" class="contact-form">:</td>
      <td width="70%" class="contact-text-form">
        <input type="text" class="contact-form-filds" name="company">
      </td>
    </tr>
    <tr>
      <td align="left" valign="top" colspan="2">
        <div class="contact-form checkbox">
          <span><label><strong>I want to hire</strong></label><strong>No.of</strong></span>
          <span><label><input type="checkbox"  name="technology" id="check_0" > iOS</label><input type="text" class="hirebox" name="tech" id="textbox_0" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_1" > Android</label><input type="text" class="hirebox" name="tech" id="textbox_1" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_2" > PHP</label><input type="text" class="hirebox" name="tech" id="textbox_2" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_3" > .NET MVC</label><input type="text" class="hirebox" name="tech" id="textbox_3" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_4" > JAVA</label><input type="text" class="hirebox" name="tech" id="textbox_4" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_5" > Database Administrator</label><input type="text" class="hirebox" name="tech" id="textbox_5" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_6" > SEO </label><input type="text" class="hirebox" name="tech" id="textbox_6" disabled="disabled"></span>
        </div>
      </td>
      <td align="left" valign="top">
        <div class="contact-form checkbox" style="margin-left:60px;">
          <span><label><strong>I want to hire</strong></label><strong>No.of</strong></span>
          <span><label><input type="checkbox"  name="technology" id="check_7"> User Interface Designer</label><input type="text" class="hirebox" name="tech" id="textbox_7" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_8"> QA</label><input type="text" class="hirebox" name="tech" id="textbox_8" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_9"> Project Manager</label><input type="text" class="hirebox" name="tech" id="textbox_9" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_10"> Business Analyst</label><input type="text" class="hirebox" name="tech" id="textbox_10" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_11"> Technical Analyst</label><input type="text" class="hirebox" name="tech" id="textbox_11" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_12"> ODOO</label><input type="text" class="hirebox" name="tech" id="textbox_12" disabled="disabled"></span>
          <span><label><input type="checkbox"  name="technology" id="check_13"> Cold Fusion</label><input type="text" class="hirebox" name="tech" id="textbox_13" disabled="disabled"></span>
        </div>
      </td>
    </tr>
    <tr style="margin-top:10px;">
      <td>&nbsp;</td>
    </tr>
    <tr class="require">
      <td valign="top" width="25%" class="contact-form" id="require">Or please give us a description of your requirements (Max:1000 characters)</td>
      <td width="5%" class="contact-form">:</td>
      <td width="70%" class="contact-text-form">
        <textarea name="requirements" class="contact-form-filds2" id="requirements" cols="1000" rows="3"></textarea>
      </td>
    </tr>
    <tr style="margin-top:10px;">
      <td>&nbsp;</td>
    </tr>
    <tr>
      <td width="35%" class="contact-form">If you have a document to share, please upload it here</td>
      <td width="5%" class="contact-form">:</td>
      <td width="70%" class="contact-text-form">
        <label class="file-upload">
          <input type="file" name="share_doc" size="27" id="share_doc" onChange="javascript:setHiddenValue();" /><i class="fa fa-cloud-upload"></i> Upload</label>
        <input id="uploadFile" class="uploadtext" />
      </td>
    </tr>
    <tr>
      <td valign="top" colspan="2" class="contact-form"></td>
      <td></td>
    </tr>
    <tr>
      <td height="45">&nbsp;</td>
      <td>&nbsp;</td>
      <td>
        <table cellspacing="0" cellpadding="0" border="0" width="100%">
          <tr>
            <td width="75">
              <input type="submit" name="formSubmit" value="Submit" class="btnsubmit">
            </td>
            <td>&nbsp;</td>
          </tr>
        </table>
      </td>
    </tr>
  </table>
</form>

for 循环，您可以使用attribute start with选择器。然后获取数字并找到文本框后，您可以使用带有回调函数的prop()进行更新

$('[id^="check_"]').click(function() {
  // selecting all element with id name start with check_
  // then binding click event
  $("#textbox_" + this.id.split('_')[1]).prop("disabled", function(i, v) {
    // getting number from id and getting textbox 
    return !v;
    // updating checked property value based on previous value
  }).focus();
  // focusing the text field
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<span><label><strong>I want to hire</strong></label><strong>No.of</strong></span>
<span><label><input type="checkbox"  name="technology" id="check_0" > iOS</label><input type="text" class="hirebox" name="tech" id="textbox_0" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_1" > Android</label><input type="text" class="hirebox" name="tech" id="textbox_1" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_2" > PHP</label><input type="text" class="hirebox" name="tech" id="textbox_2" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_3" > .NET MVC</label><input type="text" class="hirebox" name="tech" id="textbox_3" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_4" > JAVA</label><input type="text" class="hirebox" name="tech" id="textbox_4" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_5" > Database Administrator</label><input type="text" class="hirebox" name="tech" id="textbox_5" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_6" > SEO </label><input type="text" class="hirebox" name="tech" id="textbox_6" disabled="disabled"></span>
<div class="contact-form checkbox" style="margin-left:60px;">
  <span><label><strong>I want to hire</strong></label><strong>No.of</strong></span>
  <span><label><input type="checkbox"  name="technology" id="check_7"> User Interface Designer</label><input type="text" class="hirebox" name="tech" id="textbox_7" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_8"> QA</label><input type="text" class="hirebox" name="tech" id="textbox_8" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_9"> Project Manager</label><input type="text" class="hirebox" name="tech" id="textbox_9" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_10"> Business Analyst</label><input type="text" class="hirebox" name="tech" id="textbox_10" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_11"> Technical Analyst</label><input type="text" class="hirebox" name="tech" id="textbox_11" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_12"> ODOO</label><input type="text" class="hirebox" name="tech" id="textbox_12" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_13"> Cold Fusion</label><input type="text" class="hirebox" name="tech" id="textbox_13" disabled="disabled"></span>
</div>

更新：您可以简化属性更新代码，如@ArunPJohny答案

$('[id^="check_"]').click(function() {
  // selecting all element with id name start with check_
  // then binding click event
  $("#textbox_" + this.id.split('_')[1]).prop("disabled", !this.checked)
    // getting text field using number in id of checkbox
    // updating checked property value based on previous value
    .focus();
  // focusing the text field
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<span><label><strong>I want to hire</strong></label><strong>No.of</strong></span>
<span><label><input type="checkbox"  name="technology" id="check_0" > iOS</label><input type="text" class="hirebox" name="tech" id="textbox_0" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_1" > Android</label><input type="text" class="hirebox" name="tech" id="textbox_1" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_2" > PHP</label><input type="text" class="hirebox" name="tech" id="textbox_2" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_3" > .NET MVC</label><input type="text" class="hirebox" name="tech" id="textbox_3" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_4" > JAVA</label><input type="text" class="hirebox" name="tech" id="textbox_4" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_5" > Database Administrator</label><input type="text" class="hirebox" name="tech" id="textbox_5" disabled="disabled"></span>
<span><label><input type="checkbox"  name="technology" id="check_6" > SEO </label><input type="text" class="hirebox" name="tech" id="textbox_6" disabled="disabled"></span>
<div class="contact-form checkbox" style="margin-left:60px;">
  <span><label><strong>I want to hire</strong></label><strong>No.of</strong></span>
  <span><label><input type="checkbox"  name="technology" id="check_7"> User Interface Designer</label><input type="text" class="hirebox" name="tech" id="textbox_7" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_8"> QA</label><input type="text" class="hirebox" name="tech" id="textbox_8" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_9"> Project Manager</label><input type="text" class="hirebox" name="tech" id="textbox_9" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_10"> Business Analyst</label><input type="text" class="hirebox" name="tech" id="textbox_10" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_11"> Technical Analyst</label><input type="text" class="hirebox" name="tech" id="textbox_11" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_12"> ODOO</label><input type="text" class="hirebox" name="tech" id="textbox_12" disabled="disabled"></span>
  <span><label><input type="checkbox"  name="technology" id="check_13"> Cold Fusion</label><input type="text" class="hirebox" name="tech" id="textbox_13" disabled="disabled"></span>
</div>

正如我看到您的 html 结构，您可以简单地更改相应文本框的禁用属性，如下所示

$(document).on('click','input[id^="check_"]',function(){
    if($(this).prop('checked'))
    {
        $(this).parents('span').find(':text').removeAttr('disabled');
        $(this).parents('span').find(':text').focus();
        return;
    }
    $(this).parents('span').find(':text').attr('disabled','disabled');
});