Implement function to check character occurrence in a string.

Author: russom-g

practice-tdd/count.js

@@ -1,3 +1,9 @@
 export function countChar(stringOfCharacters, findCharacter) {
-  return 5
+  let count = 0;
+  for (let i = 0; i < stringOfCharacters.length; i++) {
+    if (stringOfCharacters[i] === findCharacter) {
+      count++;
+    }
+  }
+  return count;
 }