Binary Numbers
Binary numbers with only one bit set is easy to understand:
| Binary Representation | Decimal value |
|---|---|
| 00000000000000000000000000000001 | 1 |
| 00000000000000000000000000000010 | 2 |
| 00000000000000000000000000000100 | 4 |
| 00000000000000000000000000001000 | 8 |
| 00000000000000000000000000010000 | 16 |
| 00000000000000000000000000100000 | 32 |
| 00000000000000000000000001000000 | 64 |
Setting a few more bits reveals the binary pattern:
| Binary Representation | Decimal value |
|---|---|
| 00000000000000000000000000000101 | 5 (4 + 1) |
| 00000000000000000000000000001101 | 13 (8 + 4 + 1) |
| 00000000000000000000000000101101 | 45 (32 + 8 + 4 + 1) |
JavaScript binary numbers are stored in two's complement format.
This means that a negative number is the bitwise NOT of the number plus 1:
| Binary Representation | Decimal value |
|---|---|
| 00000000000000000000000000000101 | 5 |
| 11111111111111111111111111111011 | -5 |
| 00000000000000000000000000000110 | 6 |
| 11111111111111111111111111111010 | -6 |
| 00000000000000000000000000101000 | 40 |
| 11111111111111111111111111011000 | -40 |
Converting Decimal to Binary
Example
function dec2bin(dec){
return (dec >>> 0).toString(2);
}
return (dec >>> 0).toString(2);
}
Converting Binary to Decimal
Example
function bin2dec(bin){
return parseInt(bin, 2).toString(10);
}
return parseInt(bin, 2).toString(10);
}
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