javascript if true return constructor value code example

Example 1: assign this value or if it is undefined this other value javascript

var x; //variable to change
var y; //higher priority variable
var z = 12; //lower priority variable
x = !(y === undefined) ? y : z;
console.log(x); //12

Example 2: check if javascript function is true

function example(){
  return true;
}

if(example()){ 
  console.log('hello');
}else{
  console.log('bye');
}

// result: 'hello'