如何每次从 for 循环返回值

how to return value from for loop each time

本文关键字：循环 返回值 for 何每次      更新时间：2023-09-26

我想做的是当我从键盘返回 100 时按右键，当我再次按返回 200 然后返回 300 依此类推......

function looptest() {
    for (i = 100; i < 1000; i+=100) {
       result+=i;
    }
}
$(document).keydown(function (e) {
    switch (e.which) {
        case 37: // left
            // do something
            break;
        case 38: // up
            //do something
            break;
        case 39: // right
           console.log(looptest());
            break;
        case 40: // down
            //do something
            break;
        default:
            return; // exit this handler for other keys
    }
    e.preventDefault(); // prevent the default action (scroll / move caret)
});

这是我的代码，每次返回 100，我的代码有什么问题？

只需执行类似操作 

var count= 100;
$(document).keydown(function (e) {
    switch (e.which) {
        case 37: // left
            // do something
            break;
        case 38: // up
            //do something
            break;
        case 39: // right
            console.log(count)
          count=count+100;
            break;
        case 40: // down
            //do something
            break;
        default:
            return; // exit this handler for other keys
    }
    e.preventDefault(); // prevent the default action (scroll / move caret)
});

或者如果你想使用looptest()然后像下面这样更改你的函数 

count=0;
function looptest() {
   count=count+100;
}

在全局空间中分配 K=0

 $(document).keydown(function (e) {
    switch (e.which) {
        case 37: // left
            // do something
            break;
        case 38: // up
            //do something
            break;
        case 39: // right
           K+=100
            break;
        case 40: // down
            //do something
            break;
        default:
            return; // exit this handler for other keys
    }
    e.preventDefault(); // prevent the default action (scroll / move caret)
});

每次按键盘的右键时，此代码都会在i上加100。

var i = 0;
$(document).keydown(function (e) {
    switch (e.which) {
        case 37: // left
            // do something
            break;
        case 38: // up
            //do something
            break;
        case 39: // right
            i = i+100;
            console.log(i);
            break;
        case 40: // down
            //do something
            break;
        default:
            return; // exit this handler for other keys
    }
    e.preventDefault(); // prevent the default action (scroll / move caret)
});

var result = 0; 
   function looptest() {
        for (i = 100; i < 1000; i+=100) {
           result =(result + i);
        }
    }
    $(document).keydown(function (e) {
        switch (e.which) {
            case 37: // left
                // do something
                break;
            case 38: // up
                //do something
                break;
            case 39: // right
               console.log(looptest());
                break;
            case 40: // down
                //do something
                break;
            default:
                return; // exit this handler for other keys
        }
        e.preventDefault(); // prevent the default action (scroll / move caret)
    });

全局声明结果添加时它是连接，所以请将它们添加到 （）

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