JavaScript 数组去重

• 方法一

let a = [0, "a", "B", true, undefined, "", undefined, false, 0, null, 100, null, "a", "b", "", true];
console.log(a.toString());
a = fn(a);
console.log(a.toString());

function fn(a) {
    if (a instanceof Array) {
        let b = [];
        a.forEach(item => {
            if (!b.includes(item)) {
                b.push(item);
            }
        });
        return b;
    } else {
        return a;
    }
}

• 方法二

let a = [0, "a", "B", true, undefined, "", undefined, false, 0, null, 100, null, "a", "b", "", true];
console.log(a.toString());
a = fn(a);
console.log(a.toString());

function fn(a) {
    if (a instanceof Array) {
        let b = [...new Set(a)];
        return b;
    } else {
        return a;
    }
}