Let's talk operations
Ok, operations. What are they? Well, if you know how to add, subtract, multiply, and divide, you know exactly what they are.
We can use operations in a variety of ways with our variables.
Addition
We can use addition in a variety of ways. To add variables or values together, just use +. Let's see some examples.
int x = 1;
int y = 3;
int solution1 = x + y;
double a = 3.5;
double b = 4.1;
double solution2 = a + b;
String first = "Rodrick";
String last = "Heffley";
String name = first + " " + last;
System.out.println(solution1);
System.out.println(solution2);
System.out.println(name);
And the output:
4
7.6
Rodrick Heffley
So we can add ints, doubles, and Strings. Try the other primitive types and see what happens! Not all types can be added together.
What you can also see above is that we made a new variable set to the sum of two others. For example, changing the value of x changes the value of solution1.
Subtraction
To subtract variables or values, just use -. Let's see some examples.
int x = 1;
int y = 3;
int solution1 = y - x;
double a = 3.5;
double b = 4.1;
double solution2 = a - b;
System.out.println(solution1);
System.out.println(solution2);
And the output:
2
-0.5999999999999996
Notice how we weren't able to subtract Strings, hence the exclusion above.
You might also see the -0.5999999999999996 and be very confused. We'll talk about why this happens in the next lesson. (It is pretty close to -0.6 though)
Multiplication
To multiply variables or values, just use *. Let's see some examples.
int x = 1;
int y = 3;
int solution1 = x * y;
double a = 3.5;
double b = 4.1;
double solution2 = a * b;
System.out.println(solution1);
System.out.println(solution2);
And the output:
3
14.349999999999998
Division
To divide variables or values, just use /. Let's see some examples.
int x = 1;
int y = 3;
int solution1 = y / x;
double a = 3.5;
double b = 4.1;
double solution2 = a / b;
System.out.println(solution1);
System.out.println(solution2);
And the output:
3
0.853658536585366
Modulo
What is Modulo?? Modulo is an operator to get the remainder of a division operator. To use modulo, just use %. Here are some examples:
int x = 5;
int y = 2;
System.out.println(x % y);
Here's the output:
1
5 divided by 2 is 2 with a remainder of 1. That's what we get from modulo.
In the next lesson, we will learn about casting, rounding, and more ways to set variables.