ES6 判定两个数组是否相同

 1     private isEqual(arr1:number[], arr2:number[]): boolean{
 2         if(!arr1 || !arr2) {
 3             return false;
 4         } else {
 5             if(arr1.length==0 && arr2.length==0){
 6                 return true;
 7             } else if (arr1.length==0 && arr2.length!=0 || arr1.length!=0 && arr2.length==0){
 8                 return false;
 9             } else {
10                 let big: number[], small: number[];
11                 big = arr1.length>=arr2.length ? arr1: arr2;
12                 small = big===arr1? arr2: arr1;
13                 for (let x = 0; x < big.length; x++) {
14                     let b1 = big[x];
15                     if(small.indexOf(b1)==-1){
16                         return false;
17                     }           
18                 }
19                 return true;
20             }
21         }
22     }