Javascript String Prototype Helper Methods

String.prototypeHelpers.js

/**
 * Helper String Methods/Extensions to the JS String Object
 *
 * @param String search
 * @return Bool
 */

/* Easier way to check if a string contains a substring */
String.prototype.contains = String.prototype.contains || function(search) {
    return (this.indexOf(search) !== -1);
};

/* Check if a string contains any substring within an array of passed strings */
String.prototype.containsAny = String.prototype.containsAny || function(arr) {
    for (var i = 0; i < arr.length; i++) {
        if (this.indexOf(arr[i]) > -1) {
            return true;
        }
    }
    return false;
};

String.prototype.replaceAll = String.prototype.replaceAll || function(find, replacement) {
    return this.replace(new RegExp(find, 'g'), replacement);
};

/**
 * Case conversion helper methods
 *
 * @type String
 * @return String
 */
String.prototype.toTitleCase = String.prototype.toTitleCase || function() {
    return this.replace(/\w\S*/g, function(txt) {
        return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
    });
};

String.prototype.camelCaseToDashed = String.prototype.camelCaseToDashed || function() {
    return this.replace(/([a-z])([A-Z])/g, '$1-$2').toLowerCase();
};

String.prototype.toProperCase = String.prototype.toProperCase || function() {
    return this.replace(/\w\S*/g, function(txt) {
        return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
    });
};

String.prototype.toCamelCase = String.prototype.toCamelCase || function() {
    return this.replaceAll('-', '_').replaceAll('_', ' ').replace(/(?:^\w|\-[A-Z]|\b\w)/g, function(letter, index) {
        return index == 0 ? letter.toLowerCase() : letter.toUpperCase();
    }).replace(/\s+/g, '').replace('-', '');
};

String.prototype.toKebabCase = String.prototype.toKebabCase || function(uppercase = false) {
    let str = this.toCamelCase().camelCaseToDashed();
    return (uppercase ? str.toUpperCase() : str);
};

String.prototype.toSnakeCase = String.prototype.toSnakeCase || function(capitalize = false) {
    let str = this.toKebabCase().replaceAll('-', '_');
    return (capitalize ? str.replaceAll('_', ' ').toTitleCase().replaceAll(' ', '_') : str);
};

https://cdn.simpledigital.net/common/js/extensions/String.prototypeHelpers.js