export declare class StringUtils {
    /**
     * Returns a new string where given placeholder in given source string are replaced by given replacement texts.
     *
     * Example usage:
     *
     * source = "ABCDABCD"
     * placeholder = "BC"
     * replacementTexts = "Z", "Z" (REST arguments)
     * OUTPUT = "AZDAZD"
     *
     * @param {string} source
     * @param {string} placeholder
     * @param {string} replacementTexts If only one is given, this function replaces all placeholders with that single replacementText.
     * If more are given, placeholders without a corresponding replacementText will remain their original placeholder characters.
     */
    static ReplaceOccurrencesIn(source: string, placeholder: string, ...replacementTexts: string[]): string;
    static ParseString(arg: any, defaultValue?: string): string;
    static IsString(str: any): boolean;
    static IsStringWithLength(str: string): boolean;
    /**
     * Example usage:
     * str = 'File is to large to upload. Maximum file size is {0} Mb'
     * format = [FileUtils.MaxUploadSizeInMb]
     * output = File is to large to upload. Maximum file size is 3 Mb
     *
     * str = '{0} is way better than {1}'
     * format = ['Angular2','Angular1']
     * output = Angular2 is way better than Angular1
     *
     * @param str The string that contains {0} and {1} etc, for replacement by given format data
     * @param format The format replacement data
     * @returns {string}
     */
    static Format(str: string, format: any[]): string;
    static RemoveLastChars(str: string, amount: number): string;
    private static _escapeRegExp;
    static IsValidEmail(str: string): boolean;
}
