在jquery中調用var for for循環獲取請求

Question

我在$ .get的作用域中訪問var i時遇到問題。這是我的代碼：

for (var i = 0; i < printer_ids.length; i++) { 
    $.get('/get_printer_status_message/'+printer_ids[i]+'/', function(data) { 
    $('#printer_status_'+printer_ids[i]).html(data); 

    console.log(data) 
    console.log('id: #printer_status_'+printer_ids[i]); 
    console.log('current:' + $('#printer_status_'+printer_ids[i]).html()); 
    }); 
} 

我在$ .get行中定義，但不在$ .get的作用域中。如何訪問$ .get的作用域中的var i？

Answer 1

你必須捕捉到一個局部範圍的i變量：

for (var i = 0; i < printer_ids.length; i++) { 
    (function (i){ 
    $.get('/get_printer_status_message/'+printer_ids[i]+'/', function(data) { 
     $('#printer_status_'+printer_ids[i]).html(data); 

     console.log(data) 
     console.log('id: #printer_status_'+printer_ids[i]); 
     console.log('current:' + $('#printer_status_'+printer_ids[i]).html()); 
    }); 
    }(i)); 
} 

Answer 2

一個更好的重構是避免重新定義每個圈的功能：

var doIt = function (printer_id){ 
    $.get('/get_printer_status_message/'+printer_id]+'/', function(data) { 
     $('#printer_status_'+printer_id).html(data); 

     console.log(data) 
     console.log('id: #printer_status_'+printer_id); 
     console.log('current:' + $('#printer_status_'+printer_id).html()); 
    }); 
}; 

for (var i = 0; i < printer_ids.length; i++) { 
    doIt(printer_ids[i]); 
}