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

问题描述

我知道我们可以将数组值与JavaScript中的indexOf匹配.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);

是否有匹配对象的方法?例如吗?

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

由于两个对象是不同的(虽然可能是等效的)，所以不能使用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，并根据所需的属性处理匹配.例如，要匹配所有可枚举的道具:

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 已在ES2015中添加，但可以完全填充.

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

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