Objektorienteeritud programmeerimine (Narva Kolledž) 2018/19 kevad

Session 1

Operators in Java

An operator is a character that represents an action (e.g. + is an arithmetic operator that represents addition). In general, Java has seven types of operators:

1. basic arithmetic operators
2. assignment operators
3. auto-increment and auto-decrement operators
4. logical operators (will be covered next session)
5. comparison (relational) operators (will be covered next session)
6. bitwise operators (will not be covered in this material)
7. ternary operator (will not be covered in this material)

1. Basic arithmetic operators

2.Assignment operators

public class AssignmentDemo {
   public static void main(String args[]) {
      int num1 = 10;
      int num2 = 20;

      num2 = num1;
      System.out.println("= Output: "+num2);

      num2 += num1;
      System.out.println("+= Output: "+num2);

      num2 -= num1;
      System.out.println("-= Output: "+num2);

      num2 *= num1;
      System.out.println("*= Output: "+num2);

      num2 /= num1;
      System.out.println("/= Output: "+num2);

      num2 %= num1;
      System.out.println("%= Output: "+num2);
   }
}

3. Auto-increment and auto-decrement operators

Operator precedence in Java

Just like in Python and math, operator precedence determines which operator needs to be evaluated first if an expression has more than one operator (e.g. 2+3*4 is 20 or 14?). In table below, the operators with higher precedence are at the top and lower precedence at the bottom.

Summary: variables, data types, operators & common errors

Session 1