lodash/startsWith.js

import baseToString from './.internal/baseToString.js'
import toInteger from './toInteger.js'
import toString from './toString.js'

/**
 * Checks if `string` starts with the given target string.
 *
 * @since 3.0.0
 * @category String
 * @param {string} [string=''] The string to inspect.
 * @param {string} [target] The string to search for.
 * @param {number} [position=0] The position to search from.
 * @returns {boolean} Returns `true` if `string` starts with `target`,
 *  else `false`.
 * @see endsWith, includes
 * @example
 *
 * startsWith('abc', 'a')
 * // => true
 *
 * startsWith('abc', 'b')
 * // => false
 *
 * startsWith('abc', 'b', 1)
 * // => true
 */
function startsWith(string, target, position) {
  string = toString(string)

  const { length } = string
  position = position == null ? 0 : toInteger(position)
  if (position < 0) {
    position = 0
  }
  else if (position > length) {
    position = length
  }
  target = baseToString(target)
  return string.slice(position, position + target.length) == target
}

export default startsWith