如何循环遍历JavaScript对象中的所有成员，包括作为对象的值？
例如，我如何循环（分别访问“your_name”和“your_message”）？
var validation_messages = {
"key_1": {
"your_name": "jimmy",
"your_msg": "hello world"
},
"key_2": {
"your_name": "billy",
"your_msg": "foo equals bar"
}
}
当前回答
for(var key in validation_messages){
for(var subkey in validation_messages[key]){
//code here
//subkey being value, key being 'yourname' / 'yourmsg'
}
}
其他回答
AgileJon答案的优化和改进版本：
var key, obj, prop, owns = Object.prototype.hasOwnProperty;
for (key in validation_messages ) {
if (owns.call(validation_messages, key)) {
obj = validation_messages[key];
for (prop in obj ) {
// Using obj.hasOwnProperty might cause you headache if there is
// obj.hasOwnProperty = function(){return false;}
// but 'owns' will always work
if (owns.call(obj, prop)) {
console.log(prop, "=", obj[prop]);
}
}
}
}
使用Undercore.js的_.each：
_.each(validation_messages, function(value, key){
_.each(value, function(value, key){
console.log(value);
});
});
2020年，您需要不可变的通用函数
这将遍历由子对象、数组和字符串组成的多维对象，并应用自定义函数：
export const iterate = (object, func) => {
const entries = Object.entries(object).map(([key, value]) =>
Array.isArray(value)
? [key, value.map(e => iterate(e, func))]
: typeof value === 'object'
? [key, iterate(value, func)]
: [key, func(value)]
);
return Object.fromEntries(entries);
};
用法：
const r = iterate(data, e=>'converted_'+e);
console.log(r);
下面是AgileJon解决方案的改进和递归版本（演示）：
function loopThrough(obj){
for(var key in obj){
// skip loop if the property is from prototype
if(!obj.hasOwnProperty(key)) continue;
if(typeof obj[key] !== 'object'){
//your code
console.log(key+" = "+obj[key]);
} else {
loopThrough(obj[key]);
}
}
}
loopThrough(validation_messages);
此解决方案适用于各种不同的深度。
每个2
（在此处找到）：
var lunch = {
sandwich: 'ham',
age: 48,
};
lunch.forEach2(function (item, key) {
console.log(key);
console.log(item);
});
代码：
if (!Object.prototype.forEach2) {
Object.defineProperty(Object.prototype, 'forEach2', {
value: function (callback, thisArg) {
if (this == null) {
throw new TypeError('Not an object');
}
thisArg = thisArg || window;
for (var key in this) {
if (this.hasOwnProperty(key)) {
callback.call(thisArg, this[key], key, this);
}
}
}
});
}
