JavaScript: Escape a HTML string

Last update on May 30 2022 09:58:51 (UTC/GMT +8 hours)

JavaScript String: Exercise-19 with Solution

Write a JavaScript function to escape a HTML string.

Test Data:
console.log(escape_HTML('<a href="javascript-string-exercise-17.php" target="_blank">'));
Output:

<a href="javascript-string-exercise-17.php" target="_blank">

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Write a JavaScript function to escape a HTML string.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function escape_HTML(html_str) {
    'use strict';

    return html_str.replace(/[&<>"]/g, function (tag) {
		var chars_to_replace = {
            '&': '&',
            '<': '<',
            '>': '>',
            '"': '"'
        };

		return chars_to_replace[tag] || tag;
	});
}

console.log(escape_HTML('&lt;a href=&quot;javascript-string-exercise-17.php&quot; target=&quot;_blank&quot;&gt;'));

Sample Output:

<a href="javascript-string-exercise-17.php" target="_blank">

Flowchart:

Live Demo:

See the Pen JavaScript Escape a HTML string - string-ex-19 by w3resource (@w3resource) on CodePen.

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Next: Write a JavaScript function that can pad (left, right) a string to get to a determined length.

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JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04