ES6的方法
var arr = [1,2,3,4,56,5,666,2,1,77];
var arrNew = Array.from(new Set(arr));
console.log(arr.length===arrNew.length); //false
//简写
arr = [...new Set(arr )]
ES6的方法
var arr = [1,2,3,4,56,5,666,2,1,77];
var arrNew = Array.from(new Set(arr));
console.log(arr.length===arrNew.length); //false
//简写
arr = [...new Set(arr )]