In the course of their daily work, we have to traverse the object javaScript, the operation of the array is very frequent, taking the time today to summarize briefly the method frequently used to facilitate future use and reference!
javaScript traverse the object summary
1、使用Object.keys()遍历
返回一个数组,包括对象自身的(不含继承的)所有可枚举属性(不含Symbol属性).var obj = {'0':'a','1':'b','2':'c'};
Object.keys(obj).forEach(function(key){
console.log(key,obj[key]);
});
2、使用for..in..遍历
循环遍历对象自身的和继承的可枚举属性(不含Symbol属性).var obj = {'0':'a','1':'b','2':'c'};
for(var i in obj) {
console.log(i,":",obj[i]);
}
3、使用Object.getOwnPropertyNames(obj)遍历
返回一个数组,包含对象自身的所有属性(不含Symbol属性,但是包括不可枚举属性).var obj = {'0':'a','1':'b','2':'c'};
Object.getOwnPropertyNames(obj).forEach(function(key){
console.log(key,obj[key]);
});
4、使用Reflect.ownKeys(obj)遍历
返回一个数组,包含对象自身的所有属性,不管属性名是Symbol或字符串,也不管是否可枚举. var obj = {'0':'a','1':'b','2':'c'};
Reflect.ownKeys(obj).forEach(function(key){
console.log(key,obj[key]);
});
javaScript through the array summary
1, using forEach iterate
var arr=[1,2,3,4];
arr.forEach(function(val, index) {
console.log(val, index);
});
2, using the for..in traverse ..
var arr=["张三","李四","王五","赵六"];
for (var i in arr){
console.log(i,":",arr[i]);
}
3, using for-of traversal
不仅支持数组，还支持大多数类数组对象，例如DOM NodeList对象.
也支持字符串遍历，它将字符串视为一系列的Unicode字符来进行遍历.var arr=["张三","李四","王五","赵六"];
for (var value of arr){
console.log(value);
}
