/**
 * Removes all occurrences of the specified string from the left side of the current string.
 *
 * This function takes two parameters: the current string and the string to remove.
 * If the string to remove is not provided, it defaults to an empty string and the function simply trims the current string.
 *
 * @param {string} current The string to modify.
 * @param {string} [str=""] The string to remove from the left side of the current string.
 * @returns {string} The modified string with all occurrences of the specified string removed from the left side.
 * @example
 * ```typescript
 * console.log(ltrim("   hello world", " ")); // Output: "hello world"
 * console.log(ltrim("hello world", " ")); // Output: "hello world"
 * console.log(ltrim("   hello world")); // Output: "hello world"
 * ```
 */
export declare const ltrim: (current: string, str?: string) => string;
/**
 * Removes all occurrences of the specified string from the right side of the current string.
 *
 * This function takes two parameters: the current string and the string to remove.
 * If the string to remove is not provided, it defaults to an empty string and the function simply trims the current string.
 *
 * @param {string} current The string to modify.
 * @param {string} [str=""] The string to remove from the right side of the current string.
 * @returns {string} The modified string with all occurrences of the specified string removed from the right side.
 * @example
 * ```typescript
 * console.log(rtrim("test heee", "e")); // Output: "test h"
 * console.log(rtrim("hello world", " ")); // Output: "hello world"
 * console.log(rtrim("   hello world")); // Output: "   hello world"
 * ```
 */
export declare const rtrim: (current: string, str?: string) => string;
/**
 * Checks if the provided string consists only of numbers.
 *
 * This function takes two parameters: the string to check and an optional flag to indicate whether to consider decimal points.
 *
 * @param {string} str The string to check.
 * @param {boolean} [withDecimal=true] Whether to consider decimal points in the check.
 * @returns {boolean} True if the string consists only of numbers, false otherwise.
 * @example
 * ```typescript
 * console.log(isStringNumber("123")); // Output: true
 * console.log(isStringNumber("123.45")); // Output: true
 * console.log(isStringNumber("123.45", false)); // Output: false
 * console.log(isStringNumber("abc")); // Output: false
 * ```
 */
export declare const isStringNumber: (str: string, withDecimal?: boolean) => boolean;
/**
 * Extends the String interface with additional methods for string manipulation.
 */
declare global {
    interface String {
        /**
         * Removes all occurrences of the specified string from the left side of the string.
         * @param {string} [str=""] The string to remove from the left side.
         * @returns {string} The modified string with all occurrences of the specified string removed from the left side.
         */
        ltrim(str?: string): string;
        /**
         * Removes all occurrences of the specified string from the right side of the string.
         * @param {string} [str=""] The string to remove from the right side.
         * @returns {string} The modified string with all occurrences of the specified string removed from the right side.
         */
        rtrim(str?: string): string;
        /**
         * Checks if the string consists only of numbers.
         * @param {boolean} [withDecimal=true] Whether to consider decimal points in the check.
         * @returns {boolean} True if the string consists only of numbers, false otherwise.
         */
        isNumber(withDecimal?: boolean): boolean;
        /**
         * Converts the string to snake case (e.g. "hello world" becomes "hello_world").
         * @returns {string} The string in snake case.
         */
        toSnakeCase(): string;
        /**
         * Converts the string to camel case (e.g. "hello world" becomes "helloWorld").
         * @returns {string} The string in camel case.
         */
        toCamelCase(): string;
        /**
         * Converts the first character of the string to uppercase.
         * @returns {string} The string with the first character in uppercase.
         */
        upperFirst(): string;
        /**
         * Converts the first character of the string to lowercase.
         * @returns {string} The string with the first character in lowercase.
         */
        lowerFirst(): string;
        /**
         * Replaces all occurrences of the specified string with another string.
         * @param {string} find The string to replace.
         * @param {string} replace The string to replace with.
         * @returns {string} The string with all occurrences replaced.
         */
        replaceAll(find: string, replace: string): string;
    }
}
/**
 * Converts a string from camel case to snake case (e.g. "addElementComponent" becomes "ADD_ELEMENT_COMPONENT").
 *
 * This function takes a string as input, trims it, and then replaces all occurrences of camel case with underscores.
 * The resulting string is then converted to uppercase.
 *
 * @param {string} text The string to convert.
 * @returns {string} The string in snake case.
 * @example
 * ```typescript
 * console.log(toSnakeCase("thisISDifficult")); // Output: "THIS_IS_DIFFICULT"
 * console.log(toSnakeCase("thisISNT")); // Output: "THIS_ISNT"
 * console.log(toSnakeCase("addElementComponent")); // Output: "ADD_ELEMENT_COMPONENT"
 * ```
 */
export declare const toSnakeCase: (text: string) => string;
/**
 * Converts a string from snake case to camel case (e.g. "ADD_ELEMENT_COMPONENT" becomes "addElementComponent").
 *
 * This function takes a string as input, trims it, and then replaces all occurrences of underscores with uppercase letters.
 * The resulting string is then converted to camel case by making the first character lowercase.
 *
 * @param {string} text The string to convert.
 * @returns {string} The string in camel case.
 * @example
 * ```typescript
 * console.log(toCamelCase("THIS_IS_DIFFICULT")); // Output: "thisISDifficult"
 * console.log(toCamelCase("THIS_ISNT")); // Output: "thisISNT"
 * console.log(toCamelCase("ADD_ELEMENT_COMPONENT")); // Output: "addElementComponent"
 * ```
 */
export declare const toCamelCase: (text: string) => string;
/**
 * Converts the first character of a string to uppercase.
 *
 * This function takes a string as input, trims it, and then converts the first character to uppercase.
 *
 * @param {string} str The string to modify.
 * @returns {string} The modified string with the first character in uppercase.
 * @example
 * ```typescript
 * console.log(upperFirst("hello world")); // Output: "Hello world"
 * console.log(upperFirst("HELLO WORLD")); // Output: "HELLO WORLD"
 * console.log(upperFirst("")); // Output: ""
 * ```
 */
export declare const upperFirst: (str: string) => string;
/**
 * Converts the first character of a string to lowercase.
 *
 * This function takes a string as input, trims it, and then converts the first character to lowercase.
 *
 * @param {string} str The string to modify.
 * @returns {string} The modified string with the first character in lowercase.
 * @example
 * ```typescript
 * console.log(lowerFirst("Hello World")); // Output: "hello World"
 * console.log(lowerFirst("HELLO WORLD")); // Output: "hello WORLD"
 * console.log(lowerFirst("")); // Output: ""
 * ```
 */
export declare const lowerFirst: (str: string) => string;