数组 indexOf 与对象? [英] array indexOf with objects?

问题描述

我知道我们可以在 JavaScript 中用 indexOf 匹配数组值.如果匹配，则不会返回 -1.

I know we can match array values with indexOf in JavaScript. If it matches it wont return -1.

var test = [
    1, 2, 3
]

// Returns 2
test.indexOf(3);

有没有办法匹配对象?例如?

Is there a way to match objects? For example?

var test = [
    {
        name: 'Josh'
    }
]

// Would ideally return 0, but of course it's -1.
test.indexOf({ name: 'Josh' });

推荐答案

因为这两个对象是不同的(虽然可能是等价的)，所以你不能使用 indexOf.

Since the two objects are distinct (though perhaps equivalent), you can't use indexOf.

您可以将 findIndex 与回调一起使用，并根据您想要的属性处理匹配.例如，匹配所有可枚举的 props:

You can use findIndex with a callback, and handle the matching based on the properties you want. For instance, to match on all enumerable props:

var target = {name: 'Josh'};
var targetKeys = Object.keys(target);
var index = test.findIndex(function(entry) {
    var keys = Object.keys(entry);
    return keys.length == targetKeys.length && keys.every(function(key) {
        return target.hasOwnProperty(key) && entry[key] === target[key];
    });
});

示例:

var test = [
    {
        name: 'Josh'
    }
];

var target = {name: 'Josh'};
var targetKeys = Object.keys(target);
var index = test.findIndex(function(entry) {
    var keys = Object.keys(entry);
    return keys.length == targetKeys.length && keys.every(function(key) {
        return target.hasOwnProperty(key) && entry[key] === target[key];
    });
});
console.log(index);

请注意findIndex 是在 ES2015 中添加的，但完全可填充.

Note that findIndex was added in ES2015, but is fully polyfillable.

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