Implement a solution for finding the most used char found in a given string, wrote tests

Author: somekindofwallflower

04_max_chars/index.js

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+// --- Directions
+// Given a string, return the character that is most
+// commonly used in the string.
+// --- Examples
+// maxChar("abcccccccd") === "c"
+// maxChar("apple 1231111") === "1"
+
+// Tips: Convert string to object where the keys are the character and values is the number of times the character has been found
+
+function maxChar(str) {
+    // Generate object from string
+    const charMap = {};
+    let max = 0;
+    let maxChar = "";
+    for(let char of str) {
+        charMap[char] = charMap[char] + 1 || 1;
+    }
+    for (let char in charMap) {
+        if(charMap[char] > max) {
+            max = charMap[char];
+            maxChar = char;
+        }
+    }
+   return maxChar;
+}
+
+module.exports = maxChar;

04_max_chars/test.js

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+const maxChar = require('./index');
+
+test('maxChar function exists', () => {
+    expect(typeof maxChar).toEqual('function');
+});
+
+test('Finds the most frequently used char', () => {
+    expect(maxChar('a')).toEqual('a');
+    expect(maxChar('abcdefghijklmnaaaaa')).toEqual('a');
+});
+
+test('Works with numbers in the string', () => {
+    expect(maxChar('ab1c1d1e1f1g1')).toEqual('1');
+});