数组去重【JavaScript】

数组去重，并且key和val相同的对象视为相同的，需要去重。

        主函数：

/*** 数组去重* 两个属性相同的对象也认为是相同的* @param {Array} arr* @return {Array} */
function uniqueArray(arr) {const result = []// outer: 标签，标记外层循环outer: for (const element of arr) {for (const res of result) {if (equal(element, res)) {continue outer}}result.push(element)}return result
}

        辅助函数一：isPrimitive判断原始类型

function isPrimitive(val) {return val === null || (typeof val !== "object" && typeof val !== "function")
}

        辅助函数二：equal判断两个值是否相同

function equal(val1, val2) {if (isPrimitive(val1) || isPrimitive(val2)) {return Object.is(val1, val2)}const entries1 = Object.entries(val1)const entries2 = Object.entries(val2)const keys1 = Object.keys(val1)const keys2 = Object.keys(val2)if (entries1.length !== entries2.length) {return false}for (const key1 of keys1) {if (!keys2.includes(key1)) {return false}}// 双向检查才能正确判断// const obj3 = { a: 1, b: 2 }      // const obj4 = { a: 1, b: 2, c: 3 }    for (const key2 of keys2) {if (!keys1.includes(key2)) {return false}}for (const [key, value] of entries1) {if (!equal(value, val2[key])) {return false}}return true
}

        测试案例：

const arr = [{ name: "John", age: 25 },{ name: "Jane", age: 30 },{ name: "John", age: 25 }, // 重复对象[1, 2, 3],[1, 2, 3], // 重复数组"hello","hello",    // 重复字符串{ a: 1, b: undefined },{ a: 1, c: undefined }
]console.log(uniqueArray(arr))//打印
[{ name: 'John', age: 25 },{ name: 'Jane', age: 30 },[ 1, 2, 3 ],'hello',{ a: 1, b: undefined },{ a: 1, c: undefined }
]