断言两个二维数组是否相等

问题描述

给定两个二维数组，我如何断言它们是否相等?

Given two 2D arrays, how can I assert whether or not they are equal?

例如:

array1 = [[1,0],[2,1],[3,0]]
array2 = [[1,0],[2,1],[3,1]]

检查 array1 == array2 的有效方法是什么?

What is an efficient way to check whether array1 == array2?

推荐答案

如果相等是指数组内容具有相同顺序的相同元素，那么最短(虽然不是最快)的方法是:

If by equality you mean the array contents have same elements in the same order, then the shortest (though not the fastest) way will be:

JSON.stringify(array1) === JSON.stringify(array2)

这适用于任何维度的数组.

This will work with arrays of any dimensions.

更新:如果你需要一个非常快速的算法，那么简单的迭代会更好.然而，它不是万无一失的，因此要使其真正安全可靠，您需要花费更多的开发时间.以下是现代浏览器的一种可能解决方案:

UPDATE: If you need a really fast algorithm then simple iteration will work better. However it is less fool-proof, hence to make it really safe and secure you'll need to spend more development time. Here is one possible solution for modern browsers:

function equal(array1, array2) {
    if (!Array.isArray(array1) && !Array.isArray(array2)) {
        return array1 === array2;
    }

    if (array1.length !== array2.length) {
        return false;
    }

    for (var i = 0, len = array1.length; i < len; i++) {
        if (!equal(array1[i], array2[i])) {
            return false;
        }
    }

    return true;
}

以下 JSPerf 速度测试显示了该算法相对于简短的 JSON 方法的优越性:http://jsperf.com/2d-array-comparion.

The following JSPerf speed test shows the supremacy of this algorithm over the short JSON approach: http://jsperf.com/2d-array-comparion.

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