一囱挑、遍歷對象（不包含繼承屬性）
var obj = {'a':'a','b':'b','c':'c'};
Object.keys(obj).forEach(function(key){
? ? console.log(key,":",obj[key]);
});
Object.getOwnPropertyNames(obj).forEach(function(key){
? ? console.log(key,":",obj[key]);
});
Reflect.ownKeys(obj).forEach(function(key){
console.log(key,":",obj[key]);
});
二、遍歷數(shù)組
forEach
var arr=[1,2,3,4];
arr.forEach(function(val, index) {
console.log(index, ":",val);
});
for in
var arr=["張三","李四","王五","趙六"];
for (var index in arr){
console.log(index,":",arr[index]);
}
