如何比较节点js中的两个数组？ [英] How to compare two arrays in node js?

问题描述

我有两个数组，如何在单次比较中比较两个数组。

I am having two arrays, how can i compare the two arrays at single shot.

   var arr1= ["a","b","c"];
   var arr2 = ["a","c","d"]

   if(arr1 == arr2){
      console.log(true);
    }else{
      console.log(false);
    }

推荐答案

var arr1 = ["a","b","c"];
var arr2 = ["a","c","d"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        return u === arr2[i];
    })
) {
   console.log(true);
} else {
   console.log(false);
}

---

边缘情况的附注：

---

Side note for edge cases:

=== 通常被视为此类任务略有损坏，因为 NaN 意外行为：

=== is often considered slightly broken for this kind of task because NaN behaves unexpectedly:

var arr1 = ["a",NaN,"b"];
var arr2 = ["a",NaN,"b"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        return u === arr2[i];
    })
) {
   console.log(true);
} else {
   console.log(false);
}

上面的代码实际记录 false 因为 NaN！== NaN 。此外， === 无法区分 +0 与 -0 。为了涵盖这两种情况，您可以使用更强大的比较，称为egal或is，这可以很容易地实现：

The code above actually logs false because NaN !== NaN. In addition, === can't distinguish +0 from -0. To cover both of these cases, you could use a stronger comparison known as "egal" or "is", which can easily be implemented like so:

function is(a, b) {
    return a === b && (a !== 0 || 1 / a === 1 / b) // false for +0 vs -0
        || a !== a && b !== b; // true for NaN vs NaN
}

var arr1 = ["a",NaN,"b"];
var arr2 = ["a",NaN,"b"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        // Use "is" instead of "==="
        return is(u, arr2[i]);
    })
) {
   console.log(true);
} else {
   console.log(false);
}

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