ClickHouse/docs/en/sql-reference/functions/bit-functions.md

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---
toc_priority: 48
toc_title: Bit
---
# Bit Functions {#bit-functions}
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Bit functions work for any pair of types from UInt8, UInt16, UInt32, UInt64, Int8, Int16, Int32, Int64, Float32, or Float64.
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The result type is an integer with bits equal to the maximum bits of its arguments. If at least one of the arguments is signed, the result is a signed number. If an argument is a floating-point number, it is cast to Int64.
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## bitAnd(a, b) {#bitanda-b}
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## bitOr(a, b) {#bitora-b}
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## bitXor(a, b) {#bitxora-b}
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## bitNot(a) {#bitnota}
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## bitShiftLeft(a, b) {#bitshiftlefta-b}
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## bitShiftRight(a, b) {#bitshiftrighta-b}
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## bitRotateLeft(a, b) {#bitrotatelefta-b}
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## bitRotateRight(a, b) {#bitrotaterighta-b}
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## bitTest {#bittest}
Takes any integer and converts it into [binary form](https://en.wikipedia.org/wiki/Binary_number), returns the value of a bit at specified position. The countdown starts from 0 from the right to the left.
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**Syntax**
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``` sql
SELECT bitTest(number, index)
```
**Arguments**
- `number` Integer number.
- `index` Position of bit.
**Returned values**
Returns a value of bit at specified position.
Type: `UInt8`.
**Example**
For example, the number 43 in base-2 (binary) numeral system is 101011.
Query:
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``` sql
SELECT bitTest(43, 1);
```
Result:
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``` text
┌─bitTest(43, 1)─┐
│ 1 │
└────────────────┘
```
Another example:
Query:
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``` sql
SELECT bitTest(43, 2);
```
Result:
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``` text
┌─bitTest(43, 2)─┐
│ 0 │
└────────────────┘
```
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## bitTestAll {#bittestall}
Returns result of [logical conjuction](https://en.wikipedia.org/wiki/Logical_conjunction) (AND operator) of all bits at given positions. The countdown starts from 0 from the right to the left.
The conjuction for bitwise operations:
0 AND 0 = 0
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0 AND 1 = 0
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1 AND 0 = 0
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1 AND 1 = 1
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**Syntax**
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``` sql
SELECT bitTestAll(number, index1, index2, index3, index4, ...)
```
**Arguments**
- `number` Integer number.
- `index1`, `index2`, `index3`, `index4` Positions of bit. For example, for set of positions (`index1`, `index2`, `index3`, `index4`) is true if and only if all of its positions are true (`index1` ⋀ `index2`, ⋀ `index3``index4`).
**Returned values**
Returns result of logical conjuction.
Type: `UInt8`.
**Example**
For example, the number 43 in base-2 (binary) numeral system is 101011.
Query:
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``` sql
SELECT bitTestAll(43, 0, 1, 3, 5);
```
Result:
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``` text
┌─bitTestAll(43, 0, 1, 3, 5)─┐
│ 1 │
└────────────────────────────┘
```
Another example:
Query:
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``` sql
SELECT bitTestAll(43, 0, 1, 3, 5, 2);
```
Result:
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``` text
┌─bitTestAll(43, 0, 1, 3, 5, 2)─┐
│ 0 │
└───────────────────────────────┘
```
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## bitTestAny {#bittestany}
Returns result of [logical disjunction](https://en.wikipedia.org/wiki/Logical_disjunction) (OR operator) of all bits at given positions. The countdown starts from 0 from the right to the left.
The disjunction for bitwise operations:
0 OR 0 = 0
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0 OR 1 = 1
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1 OR 0 = 1
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1 OR 1 = 1
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**Syntax**
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``` sql
SELECT bitTestAny(number, index1, index2, index3, index4, ...)
```
**Arguments**
- `number` Integer number.
- `index1`, `index2`, `index3`, `index4` Positions of bit.
**Returned values**
Returns result of logical disjuction.
Type: `UInt8`.
**Example**
For example, the number 43 in base-2 (binary) numeral system is 101011.
Query:
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``` sql
SELECT bitTestAny(43, 0, 2);
```
Result:
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``` text
┌─bitTestAny(43, 0, 2)─┐
│ 1 │
└──────────────────────┘
```
Another example:
Query:
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``` sql
SELECT bitTestAny(43, 4, 2);
```
Result:
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``` text
┌─bitTestAny(43, 4, 2)─┐
│ 0 │
└──────────────────────┘
```
## bitCount {#bitcount}
Calculates the number of bits set to one in the binary representation of a number.
**Syntax**
``` sql
bitCount(x)
```
**Arguments**
- `x` — [Integer](../../sql-reference/data-types/int-uint.md) or [floating-point](../../sql-reference/data-types/float.md) number. The function uses the value representation in memory. It allows supporting floating-point numbers.
**Returned value**
- Number of bits set to one in the input number.
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The function does not convert input value to a larger type ([sign extension](https://en.wikipedia.org/wiki/Sign_extension)). So, for example, `bitCount(toUInt8(-1)) = 8`.
Type: `UInt8`.
**Example**
Take for example the number 333. Its binary representation: 0000000101001101.
Query:
``` sql
SELECT bitCount(333);
```
Result:
``` text
┌─bitCount(333)─┐
│ 5 │
└───────────────┘
```
## bitHammingDistance {#bithammingdistance}
Returns the [Hamming Distance](https://en.wikipedia.org/wiki/Hamming_distance) between the bit representations of two integer values. Can be used with [SimHash](../../sql-reference/functions/hash-functions.md#ngramsimhash) functions for detection of semi-duplicate strings. The smaller is the distance, the more likely those strings are the same.
**Syntax**
``` sql
bitHammingDistance(int1, int2)
```
**Arguments**
- `int1` — First integer value. [Int64](../../sql-reference/data-types/int-uint.md).
- `int2` — Second integer value. [Int64](../../sql-reference/data-types/int-uint.md).
**Returned value**
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- The Hamming distance.
Type: [UInt8](../../sql-reference/data-types/int-uint.md).
**Examples**
Query:
``` sql
SELECT bitHammingDistance(111, 121);
```
Result:
``` text
┌─bitHammingDistance(111, 121)─┐
│ 3 │
└──────────────────────────────┘
```
With [SimHash](../../sql-reference/functions/hash-functions.md#ngramsimhash):
``` sql
SELECT bitHammingDistance(ngramSimHash('cat ate rat'), ngramSimHash('rat ate cat'));
```
Result:
``` text
┌─bitHammingDistance(ngramSimHash('cat ate rat'), ngramSimHash('rat ate cat'))─┐
│ 5 │
└──────────────────────────────────────────────────────────────────────────────┘
```