4-4 morning challenge

4-4 morning challenge

All Rotations
Complete the function containsAllRotations that will determine if all rotations of a given string are found in a given array of strings.  That array will be unordered, and there may be extra unneeded strings in there as well.
 
To rotate a string, move the first character to the end of the string.  You may continue this process to see all possible rotations.  ex:  'dog'  --> 'ogd' --> 'gdo'
 
Note:  The original un-rotated string must also be found in the array, as it is a possible rotation.
 
Input Format:
The function will have two arguments:
str - a string.
arr - an array of strings.  
 
Output Format:
The function will return a boolean.  If arr includes every possible rotation of str, the function will return true.
 
Sample Input 1:
str:  'cat'
arr:  ['atc', 'cat', 'fish', 'tca']
 
Sample Output 1:
true
 
Explanation:  All rotations of the string 'cat' are in the array.
 
Sample Input 2:
str:  'cherry'
arr:  ['rycher', 'errych', 'cherry', 'rryche', 'herryc', 'sherry']
 
Sample Output 2:
false
 
Explanation:   The string 'ycherr' is missing.

Solution: 

function containsAllRotations(str, arr) {
	
	
	for(var i=0; i<str.length; i++) {
		str = str.slice(1) + str.charAt(0);
		if(arr.indexOf(str) === -1) {
			return false;
		}
	}
	return true;
}

containsAllRotations('cat', ['atc', 'cat', 'fish', 'tca'])