When a function calls itself, it is called recursion and the same works for JavaScript too. Let’s see an example in which a function calls itself
Example
Live Demo
<html> <body> <script> function displayFact(value) { if (value < 0) { return -1; } // 0 factorial is equal to 1 else if (value == 0) { return 1; } else { return (value * displayFact(value - 1)); } } var res = displayFact(5); document.write("5 factorial = "+res); </script> </body> </html>