Useful JavaScript Prototypes and methods

Here are some useful JavaScript prototypes and methods for various datatypes to extend your application functionalities:

1. String

   • Proper Case (Convert string to Proper/Title Case)

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

     Usage:

     'your name'.toProperCase();
     Output: 'Your Name'

   • Snake Case (Convert studly case ‘YourName’ to ‘your_name’)

     // convert string to snake case
     String.prototype.toSnakeCase = function () {
         return this.replace(/(.)([A-Z])/g, "$1_$2").toLowerCase();
     };

     Usage:

     'YourName'.toSnakeCase();
     Output: 'your_name'

   • Is Date (Check if string is a Date)

     // check if string is a valid date
     String.prototype.isDate = function () {
         var dateFormat;
     
         if (toString.call(this) === '[object Date]') {
             return true;
         }
         if (typeof this.replace === 'function') {
             this.replace(/^\s+|\s+$/gm, '');
         }
     
         dateFormat = /(^\d{1,4}[\.|\\/|-]\d{1,2}[\.|\\/|-]\d{1,4})(\s*(?:0?[1-9]:[0-5]|1(?=[012])\d:[0-5])\d\s*[ap]m)?$/;
     
         if (dateFormat.test(this)) {
             return !!new Date(this).getTime();
         }
     
         return false;
     };

     Usage:

     '12-03-1990'.isDate();
     Output: true

   • Is Time (Check if string is a Time)

     // check if string is a time
     String.prototype.isTime = function () {
         var isValid = /^([0-1]?[0-9]|2[0-3]):([0-5][0-9])(:[0-5][0-9])?$/.test(this);
         return isValid;
     };

     Usage:

     '14:36'.isTime();
     Output: true

   • Is DateTime (Check if string is DateTime, to make it working, copy the above Date & Time Prototype)

     // check if string is a time
     String.prototype.isDateTime = function () {
         var date = this.split(" ");
     
         if (date[0].isDate() && date[1].isTime()) {
             return true;
         }
     
         return false;
     };

     Usage:

     '20-10-1990 14:36'.isDateTime();
     Output: true

2. Date (Get Long and Short Month Names with Multilingual Support)

   • Month Long Name

     // getting month long name from Date object
     Date.prototype.getMonthName = function(lang) {
         lang = lang && (lang in Date.locale) ? lang : 'en';
         return Date.locale[lang].month_names[this.getMonth()];
     };

   • Month Short Name

     // getting month short name from Date object
     Date.prototype.getMonthNameShort = function(lang) {
         lang = lang && (lang in Date.locale) ? lang : 'en';
         return Date.locale[lang].month_names_short[this.getMonth()];
     };

   • Date Locale(Multilingual Support)

     Date.locale = {
         en: {
             month_names: ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
             month_names_short: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
         }
     };

     Usage:

     var current_month = new Date().getMonthName(lang);
     var current_short_name = new Date().getMonthNameShort(lang);

     lang parameter is optional

3. Array

   • Contains (Check if given element exists in Array, similar to jQuery inArray)

     Array.prototype.contains = function(obj) {
         var i = this.length;
         while (i--) {
             if (this[i] === obj) {
                 return true;
             }
         }
         return false;
     }

     Usage:

     ['Red', 'Yellow', 'Green', 'Blue'].contains('Green');
     Output: true

   • Random (Pick a random element from array)

     Array.prototype.random = function () {
         return this[Math.floor((Math.random()*this.length))];
     }

     Usage:

     [1, 2, 3, 4].random();

4.  Storage

   • Set Object in LocalStorage/SessionStorage

     Storage.prototype.setObject = function(key, value) {
         this.setItem(key, JSON.stringify(value));
     }

     Usage:

     localStorage.setObject('numbers', [1, 2, 3, 4]);

   • Get Object from LocalStorage/Session

     Storage.prototype.getObject = function(key) {
         var value = this.getItem(key);
         return value && JSON.parse(value);
     }

     Usage:

     localStorage.getObject('numbers');