How to iterate through all properties and its values in Typescript class

Question

How do I iterate through list of class properties and get the values of each (only the properties and not the functions)

class Person{
 name:string;
 age:number;
 address:Address;
 getObjectProperties(){
   let json = {};
    // I need to get the name, age and address in this JSON and return it
    // how to do this dynamically, rather than getting one by one 
    // like json["name"] = this.name;
   return json;
 }
}

Please help.

Possible duplicate of [Iterate through object properties](http://stackoverflow.com/questions/8312459/iterate-through-object-properties) — Igor, Mar 17 '17 at 19:42
Possible duplicate of [How do I loop through or enumerate a JavaScript object?](http://stackoverflow.com/questions/684672/how-do-i-loop-through-or-enumerate-a-javascript-object) — 4castle, Mar 17 '17 at 19:44

score 2 · Accepted Answer · answered Mar 17 '17 at 19:43

You can't do that, if you look at the compiled code of:

class Person {
    name: string;
    age: number;
    address: Address;
}

You'll see that those properties aren't part of it:

var Person = (function () {
    function Person() {
    }
    return Person;
}());

Only if you assign a value then the property is added:

class Person {
    name: string = "name";
}

Compiles to:

var Person = (function () {
    function Person() {
        this.name = "name";
    }
    return Person;
}());

You can use a property decorator for that.

score 0 · Answer 2 · edited May 23 '17 at 12:17

Note: I am making the assumption that you have assigned values to your fields like name. If that is not the case this will not work.

// if you want json as a string
getObjectProperties(){
   let json = JSON.stringify(this);
}

or

// if you want a copy of the fields and their values
getObjectProperties(){
   let json = JSON.parse(JSON.stringify(this));
}

or if you want to loop through the properties see duplicate Iterate through object properties

How to iterate through all properties and its values in Typescript class

2 Answers2

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