Learn for the first time java # 3 expressions and operators

What is a formula?

public class Main {
	public static void main(String[] args) {
	    int a;
	    int b;
	    a = 20;
	    b =a+5;

Execution result


Something like the 6th line is called an expression. "A", "b" and "5" are called operands, and "+" and "*" are called operators. Even if it is a complicated formula, all the formulas consist of these two.


Among operants, what is described in the source code such as "5" and "hello, world" is called a literal. Literals have data types such as (int).

Escape sequence

A special character is represented by a description method that is described by the \ symbol followed by a single character.

Notation meaning
¥” Double quote symbol
¥ ’ Quote symbol
¥¥ Yen sign
¥n new line


operator function
- subtraction
Remainder of division (remainder)
String concatenation
Substitute the right side for the left side
+= Add the left side and the right side and assign to the left side (as per the arithmetic operator)
++ Increase the value by one
--- Decrease the value by one

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