js insert variable into string es6 code example

Example 1: js string concatenation es6

let str=`JavaScript first appeared ${a+b} years ago. Wow!`;

Example 2: how to build a string javascript es6

var name = "John" ;
var age = 32 ; 

console.log(`My name is ${name}, and I'm ${age} years old.`)
//displays : My name is John, and I'm 32 years old.