Assign and use javascript property and keyword as a variable

Question

Suppose,

a = "aaa"
l = length
a.length //gives 3
a.l //gives undefined

but,
c = console.log
c(a) //gives aaa

How can I do this for .length property also?

Answer 1

You can destructure the length property:

var a = "aaa"
var { length: l } = a;
console.log(l); // 3

But the value is not dynamically linked:

a += "aa";
console.log(l); // 3

You need to refresh its value:

({ length: l } = a;
console.log(l); // 5

...

Anyway, you could access dynamically and simply by doing:

var a = "aaa", b = "bbbbb";
var l = "length";
console.log(a[l]); // 3
console.log(b[l]); // 5
a += b;
console.log(a[l]); // 8

Obviously, you could also define a getter on the String prototype as an alias of the original length property, but it's widely unadvised to alter builtin prototype...

Answer 2

You can do :
const l = a.length

Answer 3

Med Amine Fh but I have lot of strings to use .length..
So, I want to do this to reduce code size.

Answer 4

Create a function that returns or console log the length like so :

function len(x){
//console.log(x.length)
return x.length
}

and you can store the returned value like so :

const lengthA = len(a)