uniqueId()

uniqueId(prefix): string

Generates a unique ID. If prefix is given, the ID is appended to it.

note

IDs are unique within the current runtime session.

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Parameters

prefix: string = ""

The value to prefix the ID with.

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Returns: string

The unique ID string.

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Since

2.0.0

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Note

Counter resets on page reload or process restart.

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Also known as

uid (Radashi) · uniqueId (Lodash, es-toolkit) · ❌ (Remeda, Ramda, Effect, Modern Dash, Antfu)

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Example

uniqueId();         // => '1'
uniqueId();         // => '2'
uniqueId('user_');  // => 'user_3'
uniqueId('item_');  // => 'item_4'

// Use case: Generate unique keys for React
const items = data.map(item => ({
  ...item,
  key: uniqueId('item_')
}));

// Use case: Create unique DOM IDs
const modalId = uniqueId('modal_');

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How it works?

Generates a unique ID, optionally with a prefix.

Counter Mechanism

Use Cases

IDs are unique within the current runtime session.

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Use Cases

React list keys for dynamic content 📌

Generate unique keys for dynamically created list items. Essential when items lack natural unique identifiers.

#React#keys#list#dynamic#rendering

items.map(item => <Card key={uniqueId('card_')} {...item} />);
// Keys: 'card_1', 'card_2', 'card_3'...

Accessible form elements with unique IDs 📌

Create unique IDs for form elements to associate labels. Critical for accessibility compliance.

#accessible#form#ID#label#a11y#WCAG

const id = uniqueId('field_');
<label htmlFor={id}>Email</label>
<input id={id} type="email" />

Temporary entity IDs before server persistence

Create temporary IDs for optimistic updates before server assigns real IDs.

#temporary#entity#ID#optimistic#update

const tempId = uniqueId('temp_');
todos.push({ id: tempId, text, pending: true });
// Replace with real ID after API response