Javascript-选择与当前数组相同的随机数组IF，然后选择另一个

我会定义数组，使其只初始化一次。然后，我将选择一个介于0和n-2之间的随机条目m(其中n是数组大小(，并将第m个条目与n-1个条目交换并显示该条目。因此，新的选择永远不能选择当前显示的条目。

存储最后一个报价的索引并进行比较。

jsFiddle示例

var lastQuote = -1;
function quotes() {
    //Define and populate the array 
    var aquote = new Array;
    aquote[0] = "'"Your cakes are fantastic, beautiful designs and taste gorgeous!'"";
    aquote[1] = "'"I can’t believe how beautiful the cake was and how much detail there was on it.  My mum cried when she saw it and didn’t want to cut it up but we eventually persuaded her and it was really tasty.'" Sasha – Rothwell";
    aquote[2] = "'"Thank you for our wedding cake.  The fruit cake was absolutely delicious and so moist.  The flowers you made were beautiful and exactly as we imagined they would be.  We have kept the flowers and they are a great reminder of our wonderful day.'" Paul & Jane – Rutland"
    aquote[3] = "'"My husband said that the cupcakes you made for his birthday are the best he has tasted and your buttercream is divine – I have to agree!'" Dawn – Cambridgeshire"
    aquote[4] = "'"Thank you Bumble Cottage Cakes for My son’s birthday cake it was fantastic as usual I will be back soon and I can’t wait for the next one.'"Liz  – Desborough"
    //Generate a random number then print the quote from that array index
    var rdmQuote = Math.floor(Math.random() * aquote.length);   
    if (rdmQuote == lastQuote) {
        alert('quote is same as current')
    } else {
        document.getElementById("randomtestimonial").innerHTML = aquote[rdmQuote];
        lastQuote = rdmQuote;
    }
}

一种方法是将元素的内容与随机选择的新内容进行比较，并使用循环选择一个新内容，直到它们不同。

var currentContent = document.getElementById("randomtestimonial").innerHTML;
do {
  rdmQuote = aquote[Math.floor(Math.random()*aquote.length)];
} while(currentContent == rdmQuote);
document.getElementById("randomtestimonial").innerHTML = rdmQuote;

这个代码可以改进，因为如果aquote.length曾经是1，那么这将是一个无限循环。但是，希望这是一个好的起点。

我只缓存当前选择。

  <!-- Hide the script from old browsers //-->
 var _cache="";
 function quotes(){
 //Define and populate the array 
 var aquote = new Array;
   // all your quotes
 //Generate a random number then print the quote from that array index
 rdmQuote = Math.floor(Math.random()*aquote.length);
 if (_cache == rdmQuote) 
     {
         alert('quote is same as current')
     }
     else
     {
       document.getElementById("randomtestimonial") .innerHTML=aquote[rdmQuote];
 }
 _cache  = rdmQuote;
 }

只需使用一个变量来存储当前报价索引。

var current = -1;
function quotes() {
    //Define and populate the array 
    var aquote = new Array;
    aquote[0] = "'"Your cakes are fantastic, beautiful designs and taste gorgeous!'"";
    aquote[1] = "'"I can’t believe how beautiful the cake was and how much detail there was on it.  My mum cried when she saw it and didn’t want to cut it up but we eventually persuaded her and it was really tasty.'" Sasha – Rothwell";
    aquote[2] = "'"Thank you for our wedding cake.  The fruit cake was absolutely delicious and so moist.  The flowers you made were beautiful and exactly as we imagined they would be.  We have kept the flowers and they are a great reminder of our wonderful day.'" Paul & Jane – Rutland"
    aquote[3] = "'"My husband said that the cupcakes you made for his birthday are the best he has tasted and your buttercream is divine – I have to agree!'" Dawn – Cambridgeshire"
    aquote[4] = "'"Thank you Bumble Cottage Cakes for My son’s birthday cake it was fantastic as usual I will be back soon and I can’t wait for the next one.'"Liz  – Desborough"
    //Generate a random number then print the quote from that array index
    rdmQuote = Math.floor(Math.random() * aquote.length);
    if (rdmQuote == current) {
        alert('quote is same as current')
    } else {
        document.getElementById("randomtestimonial").innerHTML = aquote[rdmQuote];
        current = rdmQuote;
    }
}

你的工作比你的问题标题所暗示的要容易。您希望从数组中随机选择一个字符串，如果它与当前串相同，请选择另一个。

你已经知道如何访问这个字符串，太，做

rdmQuote = Math.floor(Math.random() * aquote.length);
if (rdmQuote == document.getElementById("randomtestimonial").innerHTML]) {
    alert('quote is same as current')
} else {
    document.getElementById("randomtestimonial").innerHTML = aquote[rdmQuote];
}

注意，我用的是双等号，而不是你用的单等号是赋值。==和===是相等比较。这仍然给你留下了一个问题，如果是一样的，该怎么办(除了提醒(。您需要do/while控制命令。

var quote = "";
do {
    rdmQuote = Math.floor(Math.random() * aquote.length);
    quote = aquote[rdmQuote];
} while (quote == document.getElementById("randomtestimonial").innerHTML;
document.getElementById("randomtestimonial").innerHTML = quote;