Es6 Default Values

es6

// ES6 - Default values:

This is a thing that other language have had for a long time, and it is nice 
that JavaScript is catching up.

function getInfo(print=false) {
  if (print) {
    console.log(this.name, this.age);
  } else {
    return `${this.name} ${this.age}`;
  }
}

getInfo();

In the above code, if the parameter print is not specified, it is automatically 
default to false so that we do not have to worry inside if it is not defined.