datatypes.js - added sumOfTwoNumbers

01week/datatypes.js

@@ -0,0 +1,118 @@
+'use strict';
+
+// 1. Write a JavaScript program to display the current day and time.
+function displayDateAndTime() {
+  return Date();
+}
+
+console.log('\n\ndisplayDateAndTime');
+console.log('------------------');
+console.log('The current date and time is: ', displayDateAndTime());
+
+
+
+// 2. Write a JavaScript program to convert a number to a string.
+function convertNumberToString(num) {
+  // ensure num is really a number, to handle strings, nulls, etc
+  const convertedNum = Number(num);
+  return convertedNum.toString();
+}
+
+console.log('\n\nconvertNumberToString');
+console.log('---------------------');
+console.log("5 should convert to '5': ", convertNumberToString(5) === '5');
+console.log("5.5 should convert to '5.5': ", convertNumberToString(5.5) === '5.5');
+console.log("5.5 should convert to '5.5': ", convertNumberToString(5.5) === '5.5');
+console.log("'five' should convert to 'NaN': ", convertNumberToString() === 'NaN');
+console.log("null should convert to '0': ", convertNumberToString(null) === '0');
+
+
+
+// 3. Write a JavaScript program to convert a string to the number.
+function convertStringToNumber(str) {
+  return Number(str);
+}
+
+console.log('\n\nconvertStringToNumber');
+console.log('---------------------');
+console.log("'5' should convert to 5: ", convertStringToNumber('5') === 5);
+console.log("'5.5' should convert to 5.5: ", convertStringToNumber('5.5') === 5.5);
+console.log("'five' should convert to NaN: ", Number.isNaN(convertStringToNumber('five')));
+console.log("'' should convert to 0: ", convertStringToNumber('') === 0);
+
+
+
+// 4. Write a JavaScript program that takes in different datatypes and prints out whether they are a:
+//    Boolean
+//    Null
+//    Undefined
+//    Number
+//    NaN
+//    String
+function getDataType(val) {
+  // NaN and null are special cases
+  if (Number.isNaN(val)) return 'NaN';
+  if (val === null) return 'null';
+
+  return typeof val;
+}
+
+console.log('\n\ngetDataType');
+console.log('-----------');
+console.log("5 should return 'number': ", getDataType(5) === 'number');
+console.log("'5' should return 'string': ", getDataType('5') === 'string');
+console.log("true should return 'boolean': ", getDataType(true) === 'boolean');
+console.log("null should return 'null': ", getDataType(null) === 'null');
+console.log("undefined should return 'undefined': ", getDataType() === 'undefined');
+console.log("NaN should return 'NaN': ", getDataType(NaN) === 'NaN');
+
+
+
+// 5. Write a JavaScript program that adds 2 numbers together.
+function sumOfTwoNumbers(num1, num2) {
+  return num1 + num2;
+}
+
+console.log('\n\nsumOfTwoNumbers');
+console.log('--------------');
+console.log('2 + 2 should equal 4: ', sumOfTwoNumbers(2, 2) === 4);
+
+
+
+// 6. Write a JavaScript program that runs only when 2 things are true.
+function printSomethingWhenBothArgsAreTrue(arg1, arg2) {
+  if (arg1 && arg2) {
+    console.log('Both arguments are true!');
+  }
+}
+
+console.log('\n\printSomethingWhenBothArgsAreTrue');
+console.log('--------------------------------');
+printSomethingWhenBothArgsAreTrue(true, false); // should print nothing
+printSomethingWhenBothArgsAreTrue(1, 2); // should print 'both args are true'
+
+// 7. Write a JavaScript program that runs when 1 of 2 things are true.
+function printSomethingWhenOneArgIsTrue(arg1, arg2) {
+  if (arg1 || arg2) {
+    console.log('At least one argument is true!');
+  }
+}
+
+console.log('\n\printSomethingWhenOneArgIsTrue');
+console.log('-----------------------------');
+printSomethingWhenOneArgIsTrue(true, false); // should print msg
+printSomethingWhenOneArgIsTrue(0, null); // should print nothing
+
+
+
+// 8. Write a JavaScript program that runs when both things are not true.
+function printSomethingWhenBothArgsAreFalse(arg1, arg2) {
+  if (!(arg1 || arg2)) {
+    console.log('Neither argument is true!');
+  }
+}
+
+console.log('\n\printSomethingWhenBothArgsAreFalse');
+console.log('---------------------------------');
+printSomethingWhenBothArgsAreFalse(true, 0);        // should not print msg
+printSomethingWhenBothArgsAreFalse(null, undefined); // should print msg

01week/rockPaperScissors.js

@@ -7,11 +7,27 @@ const rl = readline.createInterface({
   output: process.stdout
 });
 
+// a map that defines what beats what. ie, rock beats 
+// scissors, paper beats rock, etc.
+const beats = {
+  "rock": "scissors",
+  "paper": "rock",
+  "scissors": "paper",
+};
 
 function rockPaperScissors(hand1, hand2) {
-
-  // Write code here
-
+  hand1 = hand1.toLowerCase().trim();
+  hand2 = hand2.toLowerCase().trim();
+  // check for tie
+  if (hand1 === hand2) {
+    return "It's a tie!";
+  }
+  // look up what hand1 beats and see if it is hand2.
+  if (beats[hand1] === hand2) {
+    return "Hand one wins!"
+  }
+  // if not, hand 2 wins
+  return "Hand two wins!"
 }
 
 function getPrompt() {
@@ -24,9 +40,7 @@ function getPrompt() {
 }
 
 // Tests
-
 if (typeof describe === 'function') {
-
   describe('#rockPaperScissors()', () => {
     it('should detect a tie', () => {
       assert.equal(rockPaperScissors('rock', 'rock'), "It's a tie!");