📚 7.includes

💻 代码实现

Array.prototype._includes = function (value) {
    for (let i = 0; i < this.length; i++) {
        if (this[i] === value) {
            return true
        }
    }
    return false
}
let arr = [1, 2, 3, 4, 5]
console.log(arr._includes(3))
console.log(arr._includes(6))