/**
 * 判断字符串是否在源字符串的头部
 *
 * @param {string} str 字符串
 * @param {String/Number} val 值
 * @param {number} startIndex 开始索引
 * @return {string}
 */
declare function startsWith(str: any, val: any, startIndex: any): boolean;
export default startsWith;