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GlobalEventHandlers.oninput - Web APIs 编辑

The oninput property of the GlobalEventHandlers mixin is an EventHandler that processes input events on the <input>, <select>, and <textarea> elements. It also handles these events on elements where contenteditable or designMode are turned on.

Note: Unlike oninput, the onchange event handler is not necessarily called for each alteration to an element's value.

Syntax

target.oninput = functionRef;

Value

functionRef is a function name or a function expression. The function receives an InputEvent object as its sole argument.

Example

This example logs the number of characters in an <input> element, every time you modify its contents.

HTML

<input type="text" placeholder="Type something here to see its length." size="50">
<p id="log"></p>

JavaScript

let input = document.querySelector('input');
let log = document.getElementById('log');

input.oninput = handleInput;

function handleInput(e) {
  log.textContent = `The field's value is
      ${e.target.value.length} character(s) long.`;
}