100 lines
5.3 KiB
Markdown
100 lines
5.3 KiB
Markdown
|
---
|
||
|
|
title: Mutations
|
||
|
|
---
|
||
|
|
 Remember to use <a>**`Read-Search-Ask`**</a> if you get stuck. Try to pair program  and write your own code 
|
||
|
|
|
||
|
|
###  Problem Explanation:
|
||
|
|
|
||
|
|
* Return true if the string in the first element of the array contains all of the letters of the string in the second element of the array..
|
||
|
|
|
||
|
|
#### Relevant Links
|
||
|
|
|
||
|
|
* <a href='http://forum.freecodecamp.com/t/javascript-string-prototype-indexof/15936' target='_blank' rel='nofollow'>String.indexOf()</a>
|
||
|
|
|
||
|
|
##  Hint: 1
|
||
|
|
|
||
|
|
* If everything is lowercase it will be easier to compare.
|
||
|
|
|
||
|
|
> _try to solve the problem now_
|
||
|
|
|
||
|
|
##  Hint: 2
|
||
|
|
|
||
|
|
* Our strings might be easier to work with if they were arrays of characters.
|
||
|
|
|
||
|
|
> _try to solve the problem now_
|
||
|
|
|
||
|
|
##  Hint: 3
|
||
|
|
|
||
|
|
* A loop might help. Use `indexOf()` to check if the letter of the second word is on the first.
|
||
|
|
|
||
|
|
> _try to solve the problem now_
|
||
|
|
|
||
|
|
## Spoiler Alert!
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
**Solution ahead!**
|
||
|
|
|
||
|
|
##  Basic Code Solution:
|
||
|
|
|
||
|
|
**Procedural**
|
||
|
|
|
||
|
|
function mutation(arr) {
|
||
|
|
var test = arr[1].toLowerCase();
|
||
|
|
var target = arr[0].toLowerCase();
|
||
|
|
for (var i=0;i<test.length;i++) {
|
||
|
|
if (target.indexOf(test[i]) < 0)
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
 <a href='https://repl.it/CLjU/30' target='_blank' rel='nofollow'>Run Code</a>
|
||
|
|
|
||
|
|
### Code Explanation:
|
||
|
|
|
||
|
|
First we make the two strings in the array lowercase. `test` will hold what we are looking for in `target`.
|
||
|
|
Then we loop through our test characters and if any of them is not found we `return false`.
|
||
|
|
|
||
|
|
If they are _all_ found, the loop will finish without returning anything and we get to `return true`.
|
||
|
|
|
||
|
|
#### Relevant Links
|
||
|
|
|
||
|
|
* <a href='http://forum.freecodecamp.com/t/javascript-string-prototype-tolowercase/15948' target='_blank' rel='nofollow'>String.toLowerCase()</a>
|
||
|
|
* <a href='http://forum.freecodecamp.com/t/javascript-for-loop/14666s-Explained' target='_blank' rel='nofollow'>For loops</a>
|
||
|
|
|
||
|
|
##  Intermediate Code Solution:
|
||
|
|
|
||
|
|
**Declarative**
|
||
|
|
|
||
|
|
function mutation(arr) {
|
||
|
|
return arr[1].toLowerCase()
|
||
|
|
.split('')
|
||
|
|
.every(function(letter) {
|
||
|
|
return arr[0].toLowerCase()
|
||
|
|
.indexOf(letter) != -1;
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
 <a href='https://repl.it/CLjU/31' target='_blank' rel='nofollow'>Run Code</a>
|
||
|
|
|
||
|
|
### Code Explanation:
|
||
|
|
|
||
|
|
Grab the second string, lowercase and turn it into an array; then make sure _every_ one of its _letters_ is a part of the lowercased first string.
|
||
|
|
|
||
|
|
`Every` will basically give you letter by letter to compare, which we do by using `indexOf` on the first string. `indexOf` will give you -1 if the current `letter` is missing. We check that not to be the case, for if this happens even once `every` will be false.
|
||
|
|
|
||
|
|
#### Relevant Links
|
||
|
|
|
||
|
|
* <a href='http://forum.freecodecamp.com/t/javascript-string-prototype-split/15944' target='_blank' rel='nofollow'>Array.split()</a>
|
||
|
|
* <a href='http://forum.freecodecamp.com/t/javascript-array-prototype-every/14287' target='_blank' rel='nofollow'>Array.every()</a>
|
||
|
|
|
||
|
|
##  NOTES FOR CONTRIBUTIONS:
|
||
|
|
|
||
|
|
*  **DO NOT** add solutions that are similar to any existing solutions. If you think it is **_similar but better_**, then try to merge (or replace) the existing similar solution.
|
||
|
|
* Add an explanation of your solution.
|
||
|
|
* Categorize the solution in one of the following categories — **Basic**, **Intermediate** and **Advanced**. 
|
||
|
|
* Please add your username only if you have added any **relevant main contents**. ( **_DO NOT_** _remove any existing usernames_)
|
||
|
|
|
||
|
|
> See  <a href='http://forum.freecodecamp.com/t/algorithm-article-template/14272' target='_blank' rel='nofollow'>**`Wiki Challenge Solution Template`**</a> for reference.
|