Chapter 2- Data Type of Expressions & Increment/Decrement Operators

Resulting data type after arithmetic operation

• Result = byte + short => integer
• Result = short + integer => integer
• Result = long + float => float
• Result = integer + float => float
• Result = character + integer => integer
• Result = character + short => integer
• Result = long + double => double
• Result = float + double => double

Increment and Decrement operators

• a++, ++a (Increment Operators)
• a--, --a (Decrement Operators)

These will operate on all data types except Booleans.

Quick Quiz 1: Try increment and decrement operators on a Java variable

• a++ => first use the value and then increment
• ++a => first increment the value then use it

Quick Quiz 2: What will be the value of the following expression(x).

• int y=7;
• int x = ++y*8;
• value of x?
• char a = ‘B’;
• a++; (a is not ‘C’)

Code as Described in the Video

package com.company;

public class cwh_10_resulting_data_type {
    public static void main(String[] args) {
        /* byte x = 5;
        int y = 6;
        short z = 8;
        int a = y + z;
        float b = 6.54f + x;
        System.out.println(b); */

        // Increment and Decrement Operators
        int i = 56;
        // int b = i++; // first b is assigned i (56) then i is incremented
        int j = 67;
        int c = ++j; // first j is incremented then c is assigned j (68)
        System.out.println(i++);
        System.out.println(i);
        System.out.println(++i);
        System.out.println(i);
        int y = 7;
        System.out.println( ++y *8);
        char ch = 'a';
        System.out.println(++ch);
    }
}

Answers :

Quick Quiz 1 Answer :

package com.company;

public class quickquizanswers {
    public static void main(String[] args) {
        int i=50;
        int b=i++;
        System.out.println(b); //first b is assigned i(50), then i is incremented
    }
}
/*
50
 */

package com.company;

public class quickquizanswers {
    public static void main(String[] args) {
        int i=50;
        int b=i++;
        int c= i;
        System.out.println(c); //first b is assigned i(50), then i is incremented
    }
}
/*
51
 */

package com.company;

public class quickquizanswers {
    public static void main(String[] args) {
        int j=67;
        int c=++j;
        System.out.println(c); //first j is incremented then c is assigned j(68)
    }
}
/*
68
 */

Quick Quiz 2 Answer :

What will be the value of the following expression(x).

int y=7;

int x = ++y*8;

value of x?

package com.company;

public class quickquizanswers {
    public static void main(String[] args) {
        int y=7;
        int x=++y*8;
        System.out.println(x); //first y is incremented
    }
}
/*
64
 */

char a = ‘B’;

a++; (a is not ‘C’)

package com.company;

public class quickquizanswers {
    public static void main(String[] args) {
        char a='B';
        char x=a++;
        System.out.println(x);
    }
}
/*
B
 */