Adding properties to Javascript Object

Question

myTable.div will return "div_undefined". When I'm changing div: 'div_' + this.name to div: 'div_' + myTable.name it will throw an error:

Uncaught TypeError: Cannot read property 'name' of undefined at :3:26

. Any Ideas?

var myTable = {
   name: 'tablename',
   div: 'div_' + this.name
}
console.log(myTable.div);

@AnkitAgarwal I think he/she refers `this` for myTable object — Fadhly Permata, Dec 04 '18 at 10:26
We need more context. Also please say _which_ error is thrown. Better yet, post the full reproduction. — Lazar Ljubenović, Dec 04 '18 at 10:27
do something like the following `var myTable = { name: 'tablename', div: '' }` `myTable.div='div_'+myTable.name` — , Dec 04 '18 at 10:33
Solved by @Quentin through referencing to [link](https://stackoverflow.com/questions/4616202/self-references-in-object-literals-initializers) — dwing265, Dec 04 '18 at 10:35

cнŝdk · Answer 1 · 2018-12-04T10:55:48.470

You can first declare your object then add the div property:

myTable.div = 'div_' + myTable.name;

Keep in mind that objects can be always extended with more properties, if you check the MDN Object reference you can see that:

In JavaScript, objects can be seen as a collection of properties. With the object literal syntax, a limited set of properties are initialized; then properties can be added and removed.

Demo:

var myTable = {
  name: 'tablename'
};
myTable.div = 'div_' + myTable.name;
console.log(myTable);

Adding properties to Javascript Object

1 Answers1