--- title: Confirm the Ending --- ## Confirm the Ending # 🌻 Intermediate Code Solution: (Declarative approach) ```javascript function confirmEnding(str, target) { // "Never give up and good luck will find you." // -- Falcor return str.slice(str.length - target.length) === target; } confirmEnding("He has to give me a new name", "name"); ``` #### 🚀 [Run Code](https://repl.it/repls/SardonicRoundAfkgaming) # Code Explanation: - First we use the `slice` method copy the string. - In order to get the last characters in `str` equivalent to the `target`'s length we use the `slice` method. - The first parameter inside the `slice` method is the starting index and the second parameter would be the ending index. - For example `str.slice(10, 17)` would return `give me`. - In this case we only include one parameter which it will copy everything from the starting index. - We substract the length of `str` and the length of `target`, that way, we shall get the last remaining characters equivalent to the `target`'s length. - Finally we compare the return result of slice to `target` and check if they have the same characters. ### Relevant Links - [String.prototype.slice()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/slice) # ![:rotating_light:](https://forum.freecodecamp.com/images/emoji/emoji_one/rotating_light.png?v=3 ":rotating_light:")Advanced Code Solution: (using Regular Expression) ```javascript function confirmEnding(str, target) { // "Never give up and good luck will find you." // -- Falcor let re = new RegExp(target+'$','i'); return re.test(str); } console.log(confirmEnding("Bastian", "n")); ``` ## Code Explanation: - We need to make a pattern from the `target` variable that exists at the end of the string `str`. - Since we will use a variable that will change the pattern each time the function is called, we will use the constructor of the regular expression object `new RegExp(pattern[, flags])`, so we start with: `new RegExp(target)`. - Then we have to check at the end of the string, so we concatenate to the `target` variable the `$` character to match the end: `new RegExp(target+'$')`. - We use the flag `i` to ignore the case of the pattern and we have our completed RegExp: `new RegExp(target+'$','i')`, or we can ommit the flag entirely. - Finally, we are using our regular expression with the `test` method to the given string, to check if the string ends with the pattern and return true or false accordingly. ### Relevant Links - [RegExp](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp) - [RegExp.prototype.test()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/test)