2.6 - Maths in JS

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Review

Web browsers can run a scripting language called JavaScript. The syntax is very similar to C, C++, C#, Java, etc...

We learned about the console and printing to the console or screen with console.log() and alert().

Today's Lesson: 2.6 - Maths in JavaScript

Computers were designed to do mathematics quickly. Let's try!

• + and - for add and subtract

• * and / for multiply and divide

• == "is it equal" (that is important)

• != "is it not equal"

• < > <= >=

• ** for exponent: 4**2 -> 16

• Cannot assume BEDMAS - it is important to utilize brackets (or parentheses) ( ) properly!

JavaScript also has a Math object to perform more complex operations.

• Math.PI

• Math.sqrt(number)

• Math.pow(base, exponent) // same as **

• Math.random()

• So much more...

• Open your Hello World REPL from last class (you should have an HTML "Hello World" REPL from 2.5)

• We will reuse that REPL to output some math to the console.
Each item should be a new "console.log". For Example:
console.log(2 + 2); // will output 4
console.log(5 * 7.1);
// 35.5

• Have your program output the correct answers to the following when you click RUN:
6 + 5
7 - 3
3 + 4 * 2
(4 / 2) + 3
5 + 2 ** 3
9 == 3 * 3
5 == -5
Math.round(6.4854)
Math.PI

• Spend some time playing around with the Math object and do more maths in JavaScript.

Extra

• How can we get a random number between (and including) 1 to 100?

• When you print Math.PI it gives a LOT of decimals. How can we round it to 4 decimals (3.1416) using Math.round()?