任何人都可以告诉我为什么循环没有在5条目后停止? http://jsbin.com/ucuqot/edit#preview
$(document).ready(function()
{
someArray = new Array();
someArray[0] = 't5';
someArray[1] = 'z12';
someArray[2] = 'b88';
someArray[3] = 's55';
someArray[4] = 'e51';
someArray[5] = 'o322';
someArray[6] = 'i22';
someArray[7] = 'k954';
var test = findXX('o322');
});
function findXX(word)
{
$.each(someArray, function(i)
{
$('body').append('-> '+i+'<br />');
if(someArray[i] == 'someArray')
{
return someArray[i]; //<--- did not stop the loop!
}
});
}
提前致谢!
因为当你在return
循环中使用each
语句时,“非假”值将充当continue
,而false
将充当break
。你需要从false
函数返回each
。像这样的东西:
function findXX(word) {
var toReturn;
$.each(someArray, function(i) {
$('body').append('-> '+i+'<br />');
if(someArray[i] == word) {
toReturn = someArray[i];
return false;
}
});
return toReturn;
}
来自docs:
我们可以通过使回调函数返回false来在特定迭代中中断$ .each()循环。返回非false与for循环中的continue语句相同;它将立即跳到下一次迭代。
这里 :
http://jsbin.com/ucuqot/3/edit
function findXX(word)
{
$.each(someArray, function(i,n)
{
$('body').append('-> '+i+'<br />');
if(n == word)
{
return false;
}
});
}
修改了$.each
功能
$.fn.eachReturn = function(arr, callback) {
var result = null;
$.each(arr, function(index, value){
var test = callback(index, value);
if (test) {
result = test;
return false;
}
});
return result ;
}
它将在非假/非空结果上打破循环并将其返回,所以在你的情况下它会是
return $.eachReturn(someArray, function(i){
...
试试这个 ...
someArray = new Array();
someArray[0] = 't5';
someArray[1] = 'z12';
someArray[2] = 'b88';
someArray[3] = 's55';
someArray[4] = 'e51';
someArray[5] = 'o322';
someArray[6] = 'i22';
someArray[7] = 'k954';
var test = findXX('o322');
console.log(test);
function findXX(word)
{
for(var i in someArray){
if(someArray[i] == word)
{
return someArray[i]; //<--- stop the loop!
}
}
}
“我们可以通过使回调函数返回false来在特定的迭代中打破$ .each()循环。返回非false与for循环中的continue语句相同;它将立即跳到下一次迭代。”
来自http://api.jquery.com/jquery.each/
是的,这是旧的但是,只是为了回答这个问题,这可能有点简单:
function findXX(word) {
$.each(someArray, function(index, value) {
$('body').append('-> ' + index + ":" + value + '<br />');
return !(value == word);
});
}
$(function() {
someArray = new Array();
someArray[0] = 't5';
someArray[1] = 'z12';
someArray[2] = 'b88';
someArray[3] = 's55';
someArray[4] = 'e51';
someArray[5] = 'o322';
someArray[6] = 'i22';
someArray[7] = 'k954';
findXX('o322');
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
更多评论:
function findXX(myA, word) {
let br = '<br />';//create once
let myHolder = $("<div />");//get a holder to not hit DOM a lot
let found = false;//default return
$.each(myA, function(index, value) {
found = (value == word);
myHolder.append('-> ' + index + ":" + value + br);
return !found;
});
$('body').append(myHolder.html());// hit DOM once
return found;
}
$(function() {
// no horrid global array, easier array setup;
let someArray = ['t5', 'z12', 'b88', 's55', 'e51', 'o322', 'i22', 'k954'];
// pass the array and the value we want to find, return back a value
let test = findXX(someArray, 'o322');
$('body').append("<div>Found:" + test + "</div>");
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
注意:阵列.includes()
可能更适合这里https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes
或者只是.find()
得到那个https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find