Jquery each - 停止循环并返回对象

Jquery each - Stop loop and return object

提问by user970727

Can anybody tell me why the loop did not stop after the 5entry?

谁能告诉我为什么循环在5进入后没有停止？

http://jsbin.com/ucuqot/edit#preview

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!
    }   
  });  
}

回答by James Allardice

Because when you use a returnstatement inside an eachloop, a "non-false" value will act as a continue, whereas falsewill act as a break. You will need to return falsefrom the eachfunction. Something like this:

因为当您return在each循环内使用语句时，“非假”值将充当 a continue，而false将充当break. 您将需要false从该each函数返回。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; 
}

From the docs:

从文档：

We can break the $.each() loop at a particular iteration by making the callback function return false. Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration.

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。

回答by Royi Namir

here :

这里 ：

http://jsbin.com/ucuqot/3/edit

http://jsbin.com/ucuqot/3/edit

function findXX(word)
{  
  $.each(someArray, function(i,n)
  {
    $('body').append('-> '+i+'<br />');
    if(n == word)
    {
      return false;
    }   
  });  
}

回答by Peter

modified $.eachfunction

修改$.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 ;
}

it will break loop on non-false/non-empty result and return it back, so in your case it would be

它会在非假/非空结果上中断循环并将其返回，因此在您的情况下它将是

return $.eachReturn(someArray, function(i){
    ...

回答by Mark Schultheiss

"We can break the $.each() loop at a particular iteration by making the callback function return false. Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration."

“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。”

from http://api.jquery.com/jquery.each/

来自http://api.jquery.com/jquery.each/

Yea, this is old BUT, JUST to answer the question, this can be a bit simpler:

是的，这是旧的但是，只是为了回答这个问题，这可以更简单一点：

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>

A bit more with comments:

多一点评论：

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>

NOTE: array .includes()may better suit here https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes

注意：数组.includes()可能更适合这里https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes

Or just .find()to get that https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find

或者只是.find()为了得到那个https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find

回答by sangeeth kumar

Try this ...

尝试这个 ...

  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!
    }   
  }
}