Add answers for strings

app/strings.js

@@ -0,0 +1,70 @@
+exports = (typeof window === 'undefined') ? global : window;
+
+exports.stringsAnswers = {
+  reduceString: function(str, amount) {
+    var newStr = [];
+    var prevLetter;
+    var curLetter;
+    var curCount = 0;
+    for (var i=0; i<str.length; i++) {
+      curLetter = str[i];
+      // Looking at a currently repeated letter
+      // or the first letter
+      if (curLetter === prevLetter || !prevLetter) {
+        if (curCount < amount) {
+          newStr.push(curLetter);
+        }
+      curCount++;
+      } else { // Looking at a new letter
+        newStr.push(curLetter);
+        curCount = 1;
+      }
+
+    prevLetter = curLetter;
+    }
+    return newStr.join('');
+  },
+
+  wordWrap: function(str, cols) {
+    var newStr = [];
+    var words = str.split(' ');
+    var curLine = [];
+
+    for (var i=0; i<words.length; i++) {
+      // first word in the line
+      if (!curLine.length) {
+        curLine.push(words[i]);
+      } else {
+        // What the current line length would be if the current word as added
+        // including the space in between the words
+        var curLineLetterCount = curLine.join('').length;
+        var lineLengthWithWord = curLineLetterCount + words[i].length + 1;
+        if (lineLengthWithWord <= cols) {
+          curLine.push(' ');
+          curLine.push(words[i]);
+        } else { // current word needs to go on a new line
+          curLine.push('\n');
+          newStr.push(curLine.join(''));
+
+          curLine = [];
+          curLine.push(words[i]);
+        }
+      }
+    }
+
+    // handle the last word
+    if (curLine.length) {
+      newStr.push(curLine.join(''));
+    }
+
+    return newStr.join('');
+  },
+
+  reverseString: function(str) {
+    var revStrLetters = [];
+    for (var i=0; i<str.length; i++) {
+      revStrLetters.unshift(str[i]);
+    }
+    return revStrLetters.join('');
+  }
+};