Simply speaking, currying in javascript enhances the reusability of functional code with multiple arguments. It is used to transform your function to one or more arguments. Let us understand with one simple example first.<\/p>\n
Normal javascript (not using currying):<\/p>\n
\/**\r\n * Webkul Software.\r\n *\r\n * @category Webkul\r\n * @package JavaScript Concepts\r\n * @author Webkul\r\n * @copyright Copyright (c) 2010-2017 Webkul Software Private Limited (https:\/\/webkul.com)\r\n * @license https:\/\/store.webkul.com\/license.html\r\n *\/\r\nvar set = function (header, site) {\r\n console.log(header + ' ' + site);\r\n}\r\n\r\nset('visit', 'webkul.com'); \/\/ visit webkul.com\r\nset('visit', 'store.webkul.com'); \/\/ visit store.webkul.com<\/pre>\nNow using currying:<\/p>\n
\/**\r\n * Webkul Software.\r\n *\r\n * @category Webkul\r\n * @package JavaScript Concepts\r\n * @author Webkul\r\n * @copyright Copyright (c) 2010-2017 Webkul Software Private Limited (https:\/\/webkul.com)\r\n * @license https:\/\/store.webkul.com\/license.html\r\n *\/\r\nvar set = function (header) {\r\n return function (site) {\r\n console.log(header + ' ' + site);\r\n }\r\n}\r\n\r\nvar visit = set('visit');\r\nvisit('webkul.com'); \/\/ visit webkul.com\r\nvisit('store.webkul.com'); \/\/ visit store.webkul.com<\/pre>\nHere, in this example, we have passed an argument first and using that variable for passing the further argument.<\/p>\n
Now, I’m providing a better example in which\u00a0currying is used to a bit more extent and it will also help you understand it better. Here, I’m providing an example for the formatting of currency.<\/p>\n
First, I’m providing an example without using currying.<\/p>\n
\/**\r\n * Webkul Software.\r\n *\r\n * @category Webkul\r\n * @package JavaScript Concepts\r\n * @author Webkul\r\n * @copyright Copyright (c) 2010-2017 Webkul Software Private Limited (https:\/\/webkul.com)\r\n * @license https:\/\/store.webkul.com\/license.html\r\n *\/\r\nvar format = function (symbol_place, currency, decimal, value) {\r\n if (!decimal) {\r\n decimal = 2; \/\/ if decimal in not provided\r\n }\r\n if (symbol_place == 'left') {\r\n return currency + parseFloat(value).toFixed(decimal);\r\n } else {\r\n return parseFloat(value).toFixed(decimal) + currency;\r\n }\r\n}\r\n\r\nvar currency_format1 = format('left', '$', 2, '50.4343');\r\nconsole.log(currency_format1); \/\/ $50.43\r\nvar currency_format2 = format('left', '$', 4, '50.4343');\r\nconsole.log(currency_format2); \/\/ $50.4343\r\nvar currency_format3 = format('left', '\u00a3', 2, '50.4343');\r\nconsole.log(currency_format3); \/\/ \u00a350.43\r\nvar currency_format4 = format('right', '\u20ac', 2, '50.4343');\r\nconsole.log(currency_format4); \/\/ 50.43\u20ac<\/pre>\nNow, the same has been done after applying currying.<\/p>\n
\/**\r\n * Webkul Software.\r\n *\r\n * @category Webkul\r\n * @package JavaScript Concepts\r\n * @author Webkul\r\n * @copyright Copyright (c) 2010-2017 Webkul Software Private Limited (https:\/\/webkul.com)\r\n * @license https:\/\/store.webkul.com\/license.html\r\n *\/\r\nvar format = function (symbol_place) {\r\n return function (currency) {\r\n return function (decimal) {\r\n return function (value) {\r\n if (!decimal) {\r\n decimal = 2; \/\/ if decimal is not provided\r\n }\r\n if (symbol_place == 'left') {\r\n return currency + parseFloat(value).toFixed(decimal);\r\n } else {\r\n return parseFloat(value).toFixed(decimal) + currency;\r\n }\r\n }\r\n }\r\n }\r\n}\r\n\r\nvar currency_left = format('left');\r\nvar currency_right = format('right');\r\n\r\nvar usd = currency_left('$');\r\nvar pound = currency_left('\u00a3');\r\n\r\nvar usd_decimal2 = usd(2);\r\nvar usd_decimal4 = usd(4);\r\nvar pound_decimal2 = pound(2);\r\n\r\nconsole.log(usd_decimal2('50.4343')); \/\/ $50.43\r\nconsole.log(usd_decimal4('50.4343')); \/\/ $50.4343\r\nconsole.log(pound_decimal2('50.4343')); \/\/ \u00a350.43\r\n\r\nvar currency_format = format('right')('\u20ac')()('50.4343');\/\/ we can pass empty arguments as well\r\nconsole.log(currency_format); \/\/ 50.43\u20ac<\/pre>\nHere, you have noted that we have made a better use of functional code by using it for multiple\u00a0cases. You can do a lot more with the currying. Hope, this blog helps you to learn something about currying.<\/p>\n","protected":false},"excerpt":{"rendered":"