Do We Need to Use Semicolons in JavaScript

In JavaScript, Semicolons are optional. Simple statements in JavaScript are generally followed by a semicolon character, just as they are in C, C++, and Java. JavaScript, however, allows you to omit this semicolon if each of your statements is placed on a separate line. It is a good programming practice to use semicolons.

For example, the following code could be written without semicolon.

<script>
   <!--
      a = 5
      b = 10
   //-->
</script>

But when formatted in a single line as follows, you must use semicolons −

<script>
   <!--
      a = 5; b = 10;
   //-->
</script>