變量不是。每個功能

Question

我有以下之外定義？這有什麼問題？

Answer 1

有幾件事情在你的代碼來解決：

• 您需要聲明傳遞的功能以外的變量到each()。
• 如果您追加到字符串，您將需要+=運算符。
• 您正試圖從DOM對象的字符串中創建一個jQuery對象爲append();只需追加字符串。
• 您沒有關閉您的each()方法。 （由Anton斑）

success: function (xml) { 
    var html = ''; 
    $(xml).find('persons').each(function(){ 
     html += '<div class = .... things here>' 
    }) 
    $('body').append(html); 
} 

Answer 2

它是函數的局部變量，因此無法在外部訪問。

success: function (xml) { 
    $(xml).find('persons').each(function(){ 
    var html ='<div class = .... things here>' //scope is limited to each function block 
    } 
    $('body').append($(html)); // not accessible here 
} 

---

讓您的可變全球

不使用var關鍵字成爲全球

---

或

success: function (xml) { 
    var html; //make it global. 
    $(xml).find('persons').each(function(){ 
     html +='<div class = .... things here>'; 
    } 
    $('body').append($(html)); // not accessible here 
} 

Answer 3

這顯然與變量如何通過代碼查看做。簡單化有兩種類型，全球和本地。一小段代碼來解釋。

var ThisWillBeGlobal = 'hello'; 
$(document).ready(function(){ 
    // Here I can access 'ThisWillBeGlobal ', because it has been defined out of the loop 
    console.log(ThisWillBeGlobal); // Proof :) 

    var definedInsideOfFunction = 'Magic right here'; 
    console.log(definedInsideOfFunction); // This will work. Defined in functions, usable in function 
}); 
// This will work: 
console.log(ThisWillBeGlobal); // it has been defined outside the functions 

// This wont work, because it's not globally defined, it only exists in the function above 
console.log(definedInsideOfFunction); 

在你的代碼，這將使這一點：

success: function (xml) { 
    var html; // By creating the var out of the loop, it's global. 
    $(xml).find('persons').each(function(){ 
    html ='<div class = .... things here>'; // don't define var here, it won't be accessable outside this looped function 
    } 
    $('body').append(html); 
} 

Answer 4

你宣佈你在.each功能vairable試試這個：

success: function (xml) { 
    var html = ""; 
    $(xml).find('persons').each(function(){ 
    html ='<div class = .... things here>' 
    } 
    $('body').append($(html)); 
} 

Answer 5

你需要做的變量HTML全球或要使用外循環它和追加，您將需要+= operator.some這樣：

success: function (xml) { 
var html =""; 
$(xml).find('persons').each(function(){ 
html +='<div class = .... things here>' 
} 
$('body').append($(html)); 
}