Typescript Static keyword to Property method and Constructor

In this blog post, We are going to learn Static keywords with properties, methods, and constructors of a class in typescript.

Static keyword in typescript

static is a keyword that can be applied to the properties and methods of a class in typescript. Static members are accessed using directly using class names.

Typescript static properties and Method example

When you want to call any methods in a class, we will use an object instance for accessing its methods, Static methods will use class names.

In class,

• Declared static variable and non-static variable
• Declared static method and non-static method
• static methods and properties are accessed using class names
• non-static methods and variables are accessed using an instance of a class ie an object.

It gives a compilation error for the below cases.

• calling a static method with an object or instance names
• calling non-static method with class names

class MyClass {
  static staticVariable: number = 0;
  nonStaticVariable: number = 0;
  constructor() {
    console.log("constructor");
  }
  nonStaticMethod() {
    console.log("non static method");
  }
  static staticMethod() {
    console.log("Static method");
  }
}

MyClass.staticMethod(); // This works fine
let myclass1 = new MyClass();
myclass1.nonStaticMethod(); // This works fine

myclass1.staticMethod(); // Compilation Error
MyClass.nonStaticMethod(); // Compilation Error

Static Constructor typescript

when the static keyword is applied to the constructor, the Compiler gives the compilation error ‘Static modifier cannot appear on a construct declaration’. In a Typescript, a static keyword does not apply to a class constructor.

class ClassDemo {
  msg: string;
  static constructor(msg: string) {
    this.msg = message;
  }
  hello() {
    return "Hello, " + this.msg;
  }
}
let classDemo = new ClassDemo("world");

typescript static member variable and method Example

We can write a static keyword in a different way using the static method.

Declare static initialization method which will initialize data

class ClassDemo {
  static msg: string;
  constructor() {}
  static construct() {
    this.msg = "static typescript example";
    console.log("construct static method");
  }
}
console.log(ClassDemo.construct);