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String.prototype.sub()

Deprecated

Avoid using this feature in new projects. HTML wrapper methods exist only for backwards compatibility. Use DOM APIs to create elements instead. This feature may be a candidate for removal from web standards or browsers.

Consider using the following features instead: DOM.

The sub() method of String values creates a string that embeds this string in a <sub> element (<sub>str</sub>), which causes this string to be displayed as subscript.

Note: All HTML wrapper methods are deprecated and only standardized for compatibility purposes. Use DOM APIs such as document.createElement() instead.

Syntax

js
sub()

Parameters

None.

Return value

A string beginning with a <sub> start tag, then the text str, and then a </sub> end tag.

Examples

Using sub()

The code below creates an HTML string and then replaces the document's body with it:

js
const contentString = "Hello, world";

document.body.innerHTML = contentString.sub();

This will create the following HTML:

html
<sub>Hello, world</sub>

Instead of using sub() and creating HTML text directly, you should use DOM APIs such as document.createElement(). For example:

js
const contentString = "Hello, world";
const elem = document.createElement("sub");
elem.innerText = contentString;
document.body.appendChild(elem);

Specifications

Specification
ECMAScript® 2027 Language Specification
# sec-string.prototype.sub

Browser compatibility

See also