<< (left shift) / Reference / Processing.org

Name

<< (left shift)

Description

Shifts bits to the left. The number to the left of the operator is shifted the number of places specified by the number to the right. Each shift to the left doubles the number, therefore each left shift multiplies the original number by 2. Use the left shift for fast multiplication or to pack a group of numbers together into one larger number. Left shifting only works with integers or numbers which automatically convert to an integer such at byte and char.

Examples

int m = 1 << 3;   // In binary: 1 to 1000
println(m);  // Prints "8"
int n = 1 << 8;   // In binary: 1 to 100000000
println(n);  // Prints "256"
int o = 2 << 3;   // In binary: 10 to 10000
println(o);  // Prints "16"
int p = 13 << 1;  // In binary: 1101 to 11010
println(p);  // Prints "26"

// Packs four 8 bit numbers into one 32 bit number
int a = 255;  // Binary: 00000000000000000000000011111111
int r = 204;  // Binary: 00000000000000000000000011001100
int g = 204;  // Binary: 00000000000000000000000011001100
int b = 51;   // Binary: 00000000000000000000000000110011
a = a << 24;  // Binary: 11111111000000000000000000000000
r = r << 16;  // Binary: 00000000110011000000000000000000
g = g << 8;   // Binary: 00000000000000001100110000000000

// Equivalent to "color argb = color(r, g, b, a)" but faster
color argb = a | r | g | b;
fill(argb);
rect(30, 20, 55, 55);