isString

Checks if a value is a string.

isString

Signature

function isString(value: any): value is string

Parameters

• value - The value to check

Returns

true if the value is a string, false otherwise.

Examples

import { isString } from 'strio'

// Strings
isString('hello')
// true

isString('')
// true

isString(String('hello'))
// true

// Non-strings
isString(123)
// false

isString(true)
// false

isString(null)
// false

isString(undefined)
// false

isString(['array'])
// false

isString({ key: 'value' })
// false

Use Cases

import { isString } from 'strio'

// Type guard
function processInput(input: unknown): string {
  if (!isString(input)) {
    throw new Error('Input must be a string')
  }
  return input.toUpperCase() // TypeScript knows it's a string
}

// Safe string operations
function safeCapitalize(value: unknown): string {
  return isString(value) ? capitalize(value) : ''
}

Related Functions

• isEmpty - Check if empty
• isAlpha - Check if alphabetic
• isNumeric - Check if numeric

See Also

• String Validation Guide
• API Reference