what are constructor in javascript code example

Example 1: javascript constructor function

function ClassMates(name,age){
  this.name=name;
  this.age=age;
  this.displayInfo=function(){
    return this.name + "is " + this.age + "year's old!";
  }
}

let classmate1 = new ClassMates("Mike Will", 15);
classmate.displayInfo(); // "Mike Will is 15 year's old!"

Example 2: constructors javascript

function Bird() {
  this.name = "Albert";
  this.color = "blue";
  this.numLegs = 2;
}
/*
This constructor defines a Bird object with properties name, color, and
numLegs set to Albert, blue, and 2, respectively.
Constructors follow a few conventions:
-Constructors are defined with a capitalized name to distinguish them from
other functions that are not constructors.

-Constructors use the keyword this to set properties of the object they will
create. Inside the constructor, this refers to the new object it will create.

-Constructors define properties and behaviors instead of returning a value as
other functions might.
*/