Example of method chaining in JavaScript.

methodChaining.js

/** Method chaining (like jQuery uses) is an awesome programming technique --
 *
 * Here's an example of a Cat class that is built so that the methods can
 * be chained together. See example at bottom for using this.
 *
 */

class Cat {
  constructor(name) {
    this._name = name;
  }

  dance(style) {
    console.log(`${this._name} does the ${style}`);
    // the next line is what lets us "method chain"
    return this;
  }

  sing(times) {
    console.log(`${this._name} sings`, "meow! ".repeat(times));
    // the next line is what lets us "method chain"
    return this;
  }

  name(newName) {
    if (newName === undefined) {
      // getting the name can't be chained, since it needs to return the name
      return this._name;
    } else {
      this._name = newName;
      // setting a new name can allow method chaining
      return this;
    }
  }
}

let fluffy = new Cat("Fluffy");

let newName = fluffy
    .dance("tango")
    .sing(3)
    .name("Frank")
    .dance("can-can")
    .name();                  // the end expression is the name, "Frank"

console.log("newName is now", newName);

Output is:

Fluffy does the tango
Fluffy sings meow! meow! meow! 
Frank does the can-can
newName is now Frank