传递键值时返回undefined的Javascript函数

时间:2018-05-18 02:28:48

标签: javascript object key parameter-passing undefined

Console.log返回:

KEY1
未定义

我希望看到:

KEY1
["首先","第二"]

var testfunc = function(a) {
    var matrix = {
        key1: ["first", "second"],
        key2: ["third", "fourth"]
    };

    var b = matrix.a;

    console.log(a);

    console.log(b);
}

var otherfunc = function() {
    return "key1";
}

testfunc(otherfunc());

1 个答案:

答案 0 :(得分:2)

您必须使用bracket notation来访问动态媒体资源。

所以它应该是:matrix[a]而不是未定义的matrix.a



var testfunc = function(a) {
    var matrix = {
        key1: ["first", "second"],
        key2: ["third", "fourth"]
    };

    var b = matrix[a];

    console.log(a);

    console.log(b);
}

var otherfunc = function() {
    return "key1";
}

testfunc(otherfunc());






const obj = {
  x: 'x',
  y: 'y'
};

const x = 'y';
console.log(obj.x);
console.log(obj[x]);