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Version: v0.29.0

Operations

Table of Supported Operations

OperationDescriptionRequirements
+Adds two private input types togetherTypes must be private input
-Subtracts two private input types togetherTypes must be private input
*Multiplies two private input types togetherTypes must be private input
/Divides two private input types togetherTypes must be private input
^XOR two private input types togetherTypes must be integer
&AND two private input types togetherTypes must be integer
|OR two private input types togetherTypes must be integer
<<Left shift an integer by another integer amountTypes must be integer, shift must be u8
>>Right shift an integer by another integer amountTypes must be integer, shift must be u8
!Bitwise not of a valueType must be integer or boolean
<returns a bool if one value is less than the otherUpper bound must have a known bit size
<=returns a bool if one value is less than or equal to the otherUpper bound must have a known bit size
>returns a bool if one value is more than the otherUpper bound must have a known bit size
>=returns a bool if one value is more than or equal to the otherUpper bound must have a known bit size
==returns a bool if one value is equal to the otherBoth types must not be constants
!=returns a bool if one value is not equal to the otherBoth types must not be constants

Predicate Operators

<,<=, !=, == , >, >= are known as predicate/comparison operations because they compare two values. This differs from the operations such as + where the operands are used in computation.

Bitwise Operations Example

fn main(x : Field) {
let y = x as u32;
let z = y & y;
}

z is implicitly constrained to be the result of y & y. The & operand is used to denote bitwise &.

x & x would not compile as x is a Field and not an integer type.

Logical Operators

Noir has no support for the logical operators || and &&. This is because encoding the short-circuiting that these operators require can be inefficient for Noir's backend. Instead you can use the bitwise operators | and & which operate identically for booleans, just without the short-circuiting.

let my_val = 5;

let mut flag = 1;
if (my_val > 6) | (my_val == 0) {
flag = 0;
}
assert(flag == 1);

if (my_val != 10) & (my_val < 50) {
flag = 0;
}
assert(flag == 0);

Shorthand operators

Noir shorthand operators for most of the above operators, namely +=, -=, *=, /=, %=, &=, |=, ^=, <<=, and >>=. These allow for more concise syntax. For example:

let mut i = 0;
i = i + 1;

could be written as:

let mut i = 0;
i += 1;