The key concept in class variables and methods is how to define them. Classes are realistically just “special functions”. To define a class, you use the keyword class followed by the name you want to give it.
1class myClass {2 constructor(height, width) {3 this.height = height;4 this.width = width;5 }6}
When you’re defining classes make sure they are hoisted or your code will throw errors like
1var p = new myClass(); // ReferenceError2class myClass {}
It should be known that the content of a class declaration is executed in strict mode.