C# Bitwise Shift Operators
In this chapter you will learn:
Using shift operators
<< is the left shift operator and
>> is the right shift operator.
The general forms for these operators are shown here:
value < num-bits
value > num-bits
A 'left shift' shift all bits to the left and a zero bit to be brought in on the right. A 'right shift' causes all bits to be shifted right one position.
In the case of a right shift on an unsigned value, a zero is brought in on the left. In the case of a right shift on a signed value, the sign bit is preserved.
left shift
class MainClass// w ww. j a v a 2s . c o m
{
public static void Main()
{
byte byte1 = 0x9a; // binary 10011010, decimal 154
byte byte2 = 0xdb; // binary 11011011, decimal 219
byte result;
System.Console.WriteLine("byte1 = " + byte1);
System.Console.WriteLine("byte2 = " + byte2);
result = (byte) (byte1 << 1);
System.Console.WriteLine("byte1 << 1 = " + result);
}
}
The code above generates the following result.
using System; /*from w w w. ja va 2 s . co m*/
class Example {
public static void Main() {
int val = 1;
for(int i = 0; i < 8; i++) {
for(int t=128; t > 0; t = t/2) {
if((val & t) != 0) Console.Write("1 ");
if((val & t) == 0) Console.Write("0 ");
}
Console.WriteLine();
val = val << 1; // left shift
}
Console.WriteLine();
}
}
The code above generates the following result.
right shift
class MainClass/* w w w .jav a2 s. c o m*/
{
public static void Main()
{
byte byte1 = 0x9a; // binary 10011010, decimal 154
byte byte2 = 0xdb; // binary 11011011, decimal 219
byte result;
System.Console.WriteLine("byte1 = " + byte1);
System.Console.WriteLine("byte2 = " + byte2);
result = (byte) (byte1 >> 1);
System.Console.WriteLine("byte1 >> 1 = " + result);
}
}
The code above generates the following result.
using System; //from ww w.java 2 s . c o m
class Example {
public static void Main() {
int val = 128;
for(int i = 0; i < 8; i++) {
for(int t=128; t > 0; t = t/2) {
if((val & t) != 0) Console.Write("1 ");
if((val & t) == 0) Console.Write("0 ");
}
Console.WriteLine();
val = val >> 1; // right shift
}
}
}
The code above generates the following result.
Use the shift operators to multiply and divide by 2
using System; //from w w w .ja va 2 s . c o m
class Example {
public static void Main() {
int n;
n = 10;
Console.WriteLine("Value of n: " + n);
Console.WriteLine("multiply by 2");
n = n << 1;
Console.WriteLine("Value of n after n = n * 2: " + n);
Console.WriteLine("multiply by 4");
n = n << 2;
Console.WriteLine("Value of n after n = n * 4: " + n);
Console.WriteLine("divide by 2");
n = n >> 1;
Console.WriteLine("Value of n after n = n / 2: " + n);
Console.WriteLine("divide by 4");
n = n >> 2;
Console.WriteLine("Value of n after n = n / 4: " + n);
Console.WriteLine();
Console.WriteLine("reset n");
n = 10;
Console.WriteLine("Value of n: " + n);
Console.WriteLine("multiply by 2, 30 times");
n = n << 30; // data is lost
Console.WriteLine("Value of n after left-shifting 30 places: " + n);
}
}
The code above generates the following result.
Next chapter...
What you will learn in the next chapter:
- How use sizeof operator to find out the size of a type in bytes
- Syntax for sizeof operator
- Example for sizeof operator