• sort() 排序

let arr = [1,55,20,11,5,3,31];
console.log(arr.sort());  //[1, 11, 20, 3, 31, 5, 55],string排序

let arr = [1,55,20,11,5,3,31];
console.log(arr.sort((a,b)=>a-b));  //[1, 3, 5, 11, 20, 31, 55]，number排序

• 用for-in 遍歷數(shù)組
  • 過(guò)濾不符合的要求的key值

function arrayHasOwnIndex(array, prop) {
    return array.hasOwnProperty(prop) && 
        /^0$|^[1-9]\d*$/.test(prop) && 
        prop <= 4294967294; // 2^32 - 2  
}

• 遍歷數(shù)組

for (let key in arr) {
        if (arrayHasOwnIndex(arr, key)) {
            console.log(arr[key]);
        }
}

• forEach() 為數(shù)組中含有有效值的每一項(xiàng)執(zhí)行一次 callback 函數(shù)

var arr = [
      {a:1},
      {b:2},
      {c:3}
];
function foo(json) {
     //... 
};
arr.forEach(foo);  // 把數(shù)組的每一項(xiàng)作為參數(shù)，調(diào)用函數(shù)