我想比较两个数组。。。理想地、有效地。没有什么稀奇古怪的,如果它们是相同的,那就是真的,如果不是,那就是假的。毫不奇怪,比较运算符似乎不起作用。

var a1 = [1,2,3];
var a2 = [1,2,3];
console.log(a1==a2);    // Returns false
console.log(JSON.stringify(a1)==JSON.stringify(a2));    // Returns true

JSON对每个数组进行编码,但是否有一种更快或“更好”的方法来简单地比较数组而不必遍历每个值?


当前回答

这里有很多复杂的长答案,所以我只想提供一个非常简单的答案:使用toString()将数组转换为简单的逗号分隔字符串===

let a = [1, 2, 3]
let b = [1, 2, 3]
let c = [4, 2, 3]

console.log(a.toString())  // this outputs "1,2,3"
console.log(a.toString() === b.toString())  // this outputs true because "1,2,3" === "1,2,3"
console.log(a.toString() === c.toString())  // this outputs false because "1,2,3" != "4,2,3"

其他回答

选择是否比较订单:

function arraysEqual(a1, a2, compareOrder) {
    if (a1.length !== a2.length) {
        return false;
    }

    return a1.every(function(value, index) {
        if (compareOrder) {
            return value === a2[index];
        } else {
            return a2.indexOf(value) > -1;
        }
    });
}

我的解决方案比较对象,而不是数组。这将以与Tomáš相同的方式工作,因为数组是对象,但没有警告:

Object.prototype.compare_to = function(comparable){
    
    // Is the value being compared an object
    if(comparable instanceof Object){
        
        // Count the amount of properties in @comparable
        var count_of_comparable = 0;
        for(p in comparable) count_of_comparable++;
        
        // Loop through all the properties in @this
        for(property in this){
            
            // Decrements once for every property in @this
            count_of_comparable--;
            
            // Prevents an infinite loop
            if(property != "compare_to"){
                
                // Is the property in @comparable
                if(property in comparable){
                    
                    // Is the property also an Object
                    if(this[property] instanceof Object){
                        
                        // Compare the properties if yes
                        if(!(this[property].compare_to(comparable[property]))){
                            
                            // Return false if the Object properties don't match
                            return false;
                        }
                    // Are the values unequal
                    } else if(this[property] !== comparable[property]){
                        
                        // Return false if they are unequal
                        return false;
                    }
                } else {
                
                    // Return false if the property is not in the object being compared
                    return false;
                }
            }
        }
    } else {
        
        // Return false if the value is anything other than an object
        return false;
    }
    
    // Return true if their are as many properties in the comparable object as @this
    return count_of_comparable == 0;
}

最短的

对于数字数组,请尝试:

a1==''+a2

变量a1=[1,2,3];变量a2=[1,2,3];console.log(a1==“”+a2)

注意:当数组还包含字符串时,此方法将不起作用,例如a2=[1,“2,3”]。

尝试了深度平等,并且成功了

var eq = require('deep-equal');
eq({a: 1, b: 2, c: [3, 4]}, {c: [3, 4], a: 1, b: 2});

如果您正在编写测试代码,那么

import chai from 'chai';
const arr1 = [2, 1];
const arr2 = [2, 1];
chai.expect(arr1).to.eql(arr2); // Will pass. `eql` is data compare instead of object compare.