Week 2: Values, Types & Operators

Javascript Demo: Lesson 1

With the demo file today are examples of short scripts that demonstrate basic uses of values, data types, operators and conditionals. You follow by also uncommenting the commented out script. Make sure comment again before moving to the next.

After this you will open up a new HTML page to try out your own use of these scripts. In Sublime Text, save a new HTML file and then type "html" & press the tab key to generate boilerplate. Save in a "DTC 477" folder for future reference.

Values, Types and Operators

• Built-ins / native functions: alert, console.log, document.write, confirm
• Variables & input: declaring and reassigning with let and const ; getting input with prompt.
• Strings: concatenation vs. template literals (backticks `like this`).
• Core data types: Number, Boolean, String, Arrays (quick console checks).
• Basic math: + - * / and using a temporary variable.
• Shortcut operators: ++, --, +=, -=, *=, /=, %.
• Conditionals: if / else, else if, and nesting.
• Comparison operators & equality pitfalls: =, ==, ===, !=, !==, >=, <=.
• Modulus %: odd/even checks (e.g., alternating turns).

Challenge 1: Personal Greeting

Ask the viewer for their name using a prompt.

Store the name in a variable and display a greeting that includes their name.

Example output:
Hello Alex, welcome to the page!

Challenge 2: Age Calculator

Ask the viewer for their age.

Convert the string input to a number (parsInt("10")), then calculate how old they will be in 10 years.

Display both their current age and their age in 10 years.

Example output:
You are 19 years old. In 10 years, you will be 29.

Challenge 3: Yes / No Decision

Ask the viewer a yes/no question using a confirm box.

Use an if / else statement to display a different message depending on their answer.

Example:
Do you like movies?

Challenge 4: Name Inspector

Ask the user for their name using a prompt. Display:

• The length of the name
• The first letter of the name
• The name in ALL CAPS
• The name in lowercase

Challenge 5: Favorite Foods List

Create an array with three of your favorite foods (strings). Display:

• How many items are in the array
• The first item in the array
• The last item in the array

Hint: the last item uses array.length - 1.