startsWith()

startsWith(str, prefix, position): boolean

Checks if a string starts with a given prefix.

DEPRECATED

Use string.startsWith() directly instead.

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Parameters

str: string | null | undefined

The string to check.

prefix: string | null | undefined

The prefix to search for.

position: number = 0

The position to start searching from.

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Returns: boolean

true if the string starts with the prefix, false otherwise.

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See Also

• String.startsWith() - MDN
• Browser support - Can I Use

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Since

2.0.0

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Also known as

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

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Example

// ❌ Deprecated approach
startsWith('hello world', 'hello');    // => true
startsWith('hello world', 'world', 6); // => true

// ✅ Recommended approach
'hello world'.startsWith('hello');    // => true
'hello world'.startsWith('world', 6); // => true

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How it works?

Checks if string starts with the given target. Deprecated: Use string.startsWith() directly (ES2015).

Native Equivalent

// ❌ startsWith('hello', 'he')
// ✅ 'hello'.startsWith('he')

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Use Cases

Check prefix 📌

Check if string starts with value.

#starts#prefix#check#string

'hello world'.startsWith('hello');  // true

Validate protocol

Check URL protocol.

#validate#protocol#url#prefix

const isSecure = url.startsWith('https://');