如何在jQuery中限制json數據上的每個循環？

Question

有沒有一種很好的方式來循環使用jQuery每個循環僅json對象的前3項？

我正在考慮相當於.slice(start,end)函數。

var data = [ 
{"Id": 10004, "PageName": "club"}, 
{"Id": 10040, "PageName": "qaz"}, 
{"Id": 10059, "PageName": "ee"}, 
{"Id": 10089, "PageName": "dd"}, 
{"Id": 10095, "PageName": "hh"} 
]; 

$.each(data, function(i, item) { 
    alert(item.PageName); 
    // somehow break at item 3 
});​ 

Answer 1

var data = [ 
{"Id": 10004, "PageName": "club"}, 
{"Id": 10040, "PageName": "qaz"}, 
{"Id": 10059, "PageName": "ee"}, 
{"Id": 10089, "PageName": "dd"}, 
{"Id": 10095, "PageName": "hh"} 
]; 

$.each(data, function(i, item) { 
    alert(item.PageName); 
    return i<2; 
});​ 

，當你返回false每個停止。

從文檔：

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.

Answer 2

你可以試試這個

$.each(data, function(i, item) { 
    if(i>2) return false; 
    alert(item.PageName); 
});​ 

DEMO。

Answer 3

試試這個

$.each(data.slice(0,3), function(i, item) { 
    alert(item.PageName); 
});​ 

Answer 4

$.each(data, function(i){ 
    //i is 0 based, so 3 is really 2. 
    if(i == 2){ 
     //exit the loop on the 3rd iteration of the object. 
     return false; 
    } 
}); 

Answer 5

$.each($(data).slice(0,3), function(i,item){ 
    console.log("\t",item.Id); 
}); 

Answer 6

你也可以通過它使用嘗試循環for循環

這裏的它是如何做到

 for(var i =0;i<3;i++){ 

     alert("Id is"+d[i].id) ; 

    } 

而且循環遍歷整個Json數組使用以下內容

 for(var i =0;i<d.length;i++){ 

     alert("Id is"+d[i].id); 
    }