Merge pull request matthewsamuel95#891 from 2alin/add-last_digit_exp-JS

 Added last digit of exp javascript

Author: matthewsamuel95

Math/last_digit_exp/JavaScript/LastDigitOfExp.js

@@ -0,0 +1,31 @@
+/*
+* Calculates the last digit of a^b
+*   Args:
+*     a (int): Base of a^b
+*     b (int): Exponent of a^b
+*   Returns:
+*     (int): The last digit of a^b
+*/
+let last_digit_of = (a,b) => {
+  let last_digit_a = parseInt(String(a).slice(-1));
+  let exp;
+
+  if (b % 4 === 0) {
+    exp = 4;
+  } else {
+    exp = b % 4;
+  }
+
+  return (Math.pow(last_digit_a, exp) % 10)
+};
+
+
+/*
+* Test Cases
+*/
+let tests = [[3,10], [6,2], [150,530]]
+console.log("Tests:")
+for (let array of tests) {
+  console.log("last digit of " + array[0] + "^" + array [1] + " is "
+             + last_digit_of(array[0], array[1]));
+}