If all the characters in the second string are found in the first string, then return true otherwise, return false. Maybe I need to sort them which will group the duplicate characters together. Someone suggested that I try a different way of looking at the problem by rearranging the characters. Putting the strings into arrays is too slow. But, that was just adding more code on top of what I already had. I even tried using the split-join with RegEx that only took one occurrence of a character. The split will replace every occurrence of a character. This method returns true if the string contains the characters. I don't know what else I can trim down or change.Īddition: I tried looking up a String.split-join solution. The includes() method determines whether a string contains the characters of a specified string.

This code passes all the tests but, it doesn't run fast enough. I am working on a CodeWars kata that requires the code to run under a certain time limit. indexOf ( 'nice', 3 ) != - 1 //false 'a nice string'.

indexOf ( 'nice' ) != - 1 //true 'a nice string'. Like includes(), the second parameters sets the starting point: 'a nice string'. If the substring is found, it returns the index of the character that starts the string. Pre-ES6, the common way to check if a string contains a substring was to use indexOf, which is a string method that return -1 if the string does not contain the substring. includes ( 'nice', 2 ) //true Pre-ES6 alternative to includes(): indexOf() includes ( 'nice', 3 ) //false 'a nice string'. includes ( 'nice' ) //true 'a nice string'.

Includes() also accepts an optional second parameter, an integer which indicates the position where to start searching for: 'a nice string'. To use it on all browsers, use Polyfill.io or another dedicated polyfill. It’s supported in all modern browsers except Internet Explorer: This method was introduced in ES6/ES2015. The most simple one, and also the canonical one going forward, is using the includes() method on a string: 'a nice string'. JavaScript offers different ways to perform this operation. Learn the canonical way, and also find out all the options you have, using plain JavaScriptĬhecking if a string contains a substring is one of the most common tasks in any programming language. JavaScript offers many ways to check if a string contains a substring.

String includes javascript