Java reference

Integer.toBinaryString()

Writes a number in binary. Related methods are toHexString() and toOctalString().

Available since: Java 1.0

Syntax

static String toBinaryString(int i)

Parameters

Parameter	Type	Description
i	int	An integer.

Return value

StringA string of zeros and ones without leading zeros.

Examples

Binary and hex notation, and the reverse conversion:

void main() {
    IO.println(Integer.toBinaryString(10));
    IO.println(Integer.toHexString(255));
    IO.println(Integer.toString(255, 8));
    IO.println(Integer.parseInt("1010", 2));
}

Output:

Negative numbers are shown in two's complement — 32 bits:

void main() {
    IO.println(Integer.toBinaryString(-1));
    IO.println(Integer.bitCount(10));
}

Output:

11111111111111111111111111111111
2

Notes

Leading zeros are not printed. To get, say, 8 digits, use String.format("%8s", Integer.toBinaryString(5)).replace(' ', '0').

Related recipes

In the tutorial

Primitive types — Java's eight primitive types: int, long, double, float, char, boolean, byte and short, their ranges and overflow.

Thanks for reading!