動態級聯

Question

比方說，我有一個數據數組和變量（或多個變量）

var i = 1; 
var arr = { 
     1: ['whatever' + i,'there are ' + i + ' dogs in the yard.', etc], 
    } 

有沒有辦法來動態地在稍後更新數組中的變量（一個或多個）功能？

所以

function start() { 
i++; 
alert(arr[1][0]); 
} 

將輸出「whatever2」而不是「whatever1」

Answer 1

你可以使用函數來代替：

var i = 1; 
var arr = { 
    1: [ 
     function() { return 'whatever' + i }, 
     function() { return 'there are ' + i + ' dogs in the yard.' }, 
     function() { return 'etc' } 
    ], 
}: 

這將改變您的來電到：

function start() { 
    i++; 
    alert(arr[1][0]()); 
} 

Answer 2

你可以有你需要一個數組和push()東西，但該字符串由時，它不會改變了。

var array = ['whatever',i,'there are ',i,' dogs in the yard.']; 
array.push('more stuff'); 
array.push('even more stuff'); 
var string = array.join('') 
//string = 'whatever[whatever "i" is during join]there are[whatever "i" is during join]dogs in the yard.more stuffeven more stuff' 

Answer 3

試試這個代碼：

var arr = function(i){ 
    return { 
     1: ['whatever' + i,'there are ' + i + ' dogs in the yard.', etc], 
    } 
} 
var anyNumber = 1; 
var updatedVar = arr(anyNumber); 

Answer 4

您可以使用eval（）：

var i = 1; 
    var arr = { 
      1: ["'whatever' + i","'there are ' + i + ' dogs in the yard.'"], 
     } 
    function start() { 
    i++; 
    alert(eval(arr[1][0])); 
    }