escapeHtml()

Escape HTML special characters in a string.

import { escapeHtml } from "@unifast/core";

Signature

function escapeHtml(str: string): string

Parameters

str

PropertyTypeDefaultDescription
strstring—The string containing characters to escape

Returns

string — The input string with &, <, >, and " replaced by their HTML entity equivalents.

Usage

import { escapeHtml } from "@unifast/core";

const safe = escapeHtml('<script>alert("xss")</script>');

console.log(safe);
// &lt;script&gt;alert(&quot;xss&quot;)&lt;/script&gt;

Examples

Basic escaping

import { escapeHtml } from "@unifast/core";

console.log(escapeHtml("Tom & Jerry"));
// Tom &amp; Jerry

console.log(escapeHtml('class="main"'));
// class=&quot;main&quot;

console.log(escapeHtml("1 < 2 > 0"));
// 1 &lt; 2 &gt; 0

Escaping user-generated content

import { escapeHtml } from "@unifast/core";

const userComment = '<img src=x onerror="alert(1)">';
const html = `<div class="comment">${escapeHtml(userComment)}</div>`;

console.log(html);
// <div class="comment">&lt;img src=x onerror=&quot;alert(1)&quot;&gt;</div>

Building safe HTML attributes

import { escapeHtml } from "@unifast/core";

const title = 'He said "hello" & waved';
const html = `<span title="${escapeHtml(title)}">Hover me</span>`;

console.log(html);
// <span title="He said &quot;hello&quot; &amp; waved">Hover me</span>

Behavior

  • & is replaced with &amp;

  • < is replaced with &lt;

  • > is replaced with &gt;

  • " is replaced with &quot;

  • All other characters are left unchanged