javascript - 如何从外部文件 JSON 创建 JAVASCRIPT ARRAY

Question

从 json 文件创建 JavaScript 数组的最佳方法是什么？我有四个空的 JavaScript 数组，我想用从 json 文件导入的数据填充它们。

var firstname = new Array();
var address= new Array();
var city = new Array();

文件 Json :“file.json”

[
{"name ": "John", "address": "350 Fifth Avenue", "city ": "New York"},
{"name ": "Mark", "address": "1101 Arch St", "city ": "Philadelphia"},
{"name ": "Jack", "address": "60th Street", "city ": "Chicago"}
]

我尝试:

$.getJSON('file.json',function (data) {   

    for (var i = 0; i < data.length; i++) {
        firstname.push.apply( firstname, data[i].firstname );
        address.push.apply( address, data[i].address );
        city.push.apply( city, data[i].city );
    }

});

但是数组仍然是空的。提前致谢

==================================已解决============== =================

$.ajax({
    async: false,
    url: 'file.json',
    data: "",
    accepts:'application/json',
    dataType: 'json',
    success: function (data) {
        for (var i = 0; i < data.length; i++) {
            firstname.push( data[i].firstname );
            address.push( data[i].address );
            city.push( data[i].city );
        }
    }
})
// Get arrays outside callback function
console.log('result: '+firstname.length); // result: 3

Answer 1

您似乎顺序错误，data 是数组，所以不是

data.name[i]

但是

data[i].name

并删除奇怪的apply它将是

$.getJSON('json.js',function (data) {   
    for (var i = 0; i < data.length; i++) {
        name.push( data[i].name );
        address.push( data[i].address );
        city.push( data[i].city );
    }
});

另请注意，对于全局上下文中的变量名称来说，name 是一个糟糕的选择。