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Function Expressions

Easy

In plain terms

A function can be stored in a variable. const fn = function() {} is a function expression. Unlike declarations, expressions are not hoisted. Anonymous functions have no name.

What you need to know

  • •Stored in variable
  • •Not hoisted
  • •Can be anonymous or named

Try it yourself

Copy the code below and run it in your browser console or a code editor:

const sayHi = function() {
  console.log('Hi');
};
sayHi();

const add = function(a, b) {
  return a + b;
};

// Pass as callback
setTimeout(function() {
  console.log('Later');
}, 1000);

// Named expression (for recursion)
const factorial = function fact(n) {
  return n <= 1 ? 1 : n * fact(n - 1);
};

Learn more

Dive deeper with these trusted resources:

MDNjavascript.infoTutorialsPointW3Schools