Call By value and Call by reference

call by value or passed by value

let a = 10;
let b = a;

so in this example, variable b is storing the value of a. if we change the variable b, then only variable b will affects not variable a, because both are in different memory location. this is mean by passed by value.

call by reference or passed by reference

let a = {
	name : 'shreyesh',
        age : 20
    }       
 let b = a 

here b is storing the address or reference of variable a. and if we modify b like b.name = 'vaibhav'; so the original a will also affect becouse the momory location is same for a and b. this term known as passed by reference