如何从数组json对象访问值 - javascript [重复]

Question

我是初学者，请帮我从下面的数组 json 对象中获取价值。

[{"Category":"HI","Sub Category":"AQ HIOP"},
{"Category":"2HJ","Sub Category":"AS HIOP"},
{"Category":"3HJ","Sub Category":"AT HIOP"},
{"Category":"4Hj","Sub Category":"AP HIOP"},
{"Category":"5HJ","Sub Category":"AN HIOP"},
]

我只需要子类别的值

提前致谢。

Answer 1

试试这个：

var arr = [{"Category":"HI","Sub Category":"AQ HIOP"},
    {"Category":"2HJ","Sub Category":"AS HIOP"},
    {"Category":"3HJ","Sub Category":"AT HIOP"},
    {"Category":"4Hj","Sub Category":"AP HIOP"},
    {"Category":"5HJ","Sub Category":"AN HIOP"},
    ]
    for (var i = 0; i < arr.length; i++) {
    	for (key in arr[i]) {
    		console.log('Key: '+ key + ' Value: ' + arr[i][key]);
    	}
    }

您可以使用for 和for in 访问您的Objet

Answer 2

您有多种方法可以做到这一点。如果你有你的对象在一个变量中，你可以像这样访问：

var test = [{"Category":"HI","Sub Category":"AQ HIOP"},
{"Category":"2HJ","Sub Category":"AS HIOP"},
{"Category":"3HJ","Sub Category":"AT HIOP"},
{"Category":"4Hj","Sub Category":"AP HIOP"},
{"Category":"5HJ","Sub Category":"AN HIOP"},
]

test[0]["Sub Category"] //Take into account that you have an array

如果您的密钥中没有任何空格，您可以这样访问：

test[0].Category;

如果你的 JSON 是字符串，你必须先使用 JSON.parse。

编辑

这里你有如何插入一个新数组

var another_array = []
another_array.push({"New category": test[0]["Sub Category"]})

Answer 3

var test = [
{"Category":"HI","Sub Category":"AQ HIOP"},
{"Category":"2HJ","Sub Category":"AS HIOP"},
{"Category":"3HJ","Sub Category":"AT HIOP"},
{"Category":"4Hj","Sub Category":"AP HIOP"},
{"Category":"5HJ","Sub Category":"AN HIOP"},
];
test.forEach(function(item){
    console.log(item);
})