Underscore.js is a javascript library that provides helper functions in functional programming without extending the built-in objects. This package consists of 100 functions like map, filter, etc.
We can install this by using npm.
npm install underscore
Syntax:
const _ = require('underscore');Approach:
- Write your markup code regarding the requirement.
- We should always place the underscore.js code inside the <script> tag.
- In this case, Write the if and else logic based upon a problem statement.
- Once the code is error-free we can surf the file as usual.
- In this way, we need to write the code in <script> tag;
Example: This example shows the use of the above-explained approach.
html
<!DOCTYPE html> <html>
<head>
<script type="text/javascript"
src=
</script>
</head>
<body>
<script type="text/javascript">
<% if (typeof (number) != "undefined") {%>
<span class="number"><%= number %></span>
<%}
else {
print("Number doesn't exist");
} %>
</script>
</body>
</html>
|
Output:
Number doesn't exist