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What Is a Function Body in Programming?

A function's body is where you place a sequence of statements you want to execute.

Syntax of a JavaScript Function Body​

function nameOfFunction() {
  // function's body
}

Function Body Examples​

Below are examples of how we use the function body.

How to define a function with three statements in its body​

function getName() {
  const firstName = "Oluwatobi";
  const lastName = "Sofela";
  console.log(firstName + " " + lastName);
}

Try it on StackBlitz

In the snippet above, the function's body contains three statements that the computer will execute whenever the function gets invoked.

Note: console.log() is a method we use to log (write) messages to a web console.

How to define a function with two statements in its body​

const bestColors = ["Coral", "Blue", "DeepPink"];

function updateMyBestColors(previousColors, newColor) {
  const mybestColors = [...previousColors, newColor];
  return mybestColors;
}

updateMyBestColors(bestColors, "GreenYellow");

Try it on StackBlitz

In the snippet above, the function's body contains two statements that the computer will execute whenever the function gets invoked.

note
  • The three dots we prepended to previousColors is called a spread operator. We used it to expand the array argument into individual elements.
  • You can also prepend the newColor parameter with a rest operator if you wish to add two or more new colors.
  • The return keyword ends its function's execution and returns the specified expression (or undefined if you provide no expression).

Overview​

This article discussed what a function body is. We also used JavaScript examples to see how it works.