add

Number → Number → Number

Added in v0.1.0

Adds two values.

See also subtract.

R.add(2, 3);       //=>  5
R.add(7)(10);      //=> 17

divide

Number → Number → Number

Parameters

• aThe first value.

• bThe second value.

Returns Number The result of a / b.

Added in v0.1.0

Divides two numbers. Equivalent to a / b.

See also multiply.

R.divide(71, 100); //=> 0.71
const half = R.divide(R.__, 2);
half(42); //=> 21
const reciprocal = R.divide(1);
reciprocal(4);   //=> 0.25

multiply

Number → Number → Number

Parameters

• aThe first value.
• bThe second value.

Returns Number The result of a * b.

Added in v0.1.0

Multiplies two numbers. Equivalent to a * b but curried.

See also divide.

const double = R.multiply(2);
const triple = R.multiply(3);
double(3);       //=>  6
triple(4);       //=> 12
R.multiply(2, 5);  //=> 10

product

[Number] → Number

Parameters

• listAn array of numbers

Returns Number The product of all the numbers in the list.

Added in v0.1.0

Multiplies together all the elements of a list.

See also reduce.

R.product([2,4,6,8,100,1]); //=> 38400

subtract

Number → Number → Number

Parameters

• aThe first value.
• bThe second value.

Returns Number The result of a - b.

Added in v0.1.0

Subtracts its second argument from its first argument.

See also add.

R.subtract(10, 8); //=> 2
const minus5 = R.subtract(R.__, 5);
minus5(17); //=> 12
const complementaryAngle = R.subtract(90);
complementaryAngle(30); //=> 60
complementaryAngle(72); //=> 18

sum

[Number] → Number

Parameters

• listAn array of numbers

Returns Number The sum of all the numbers in the list.

Added in v0.1.0

Adds together all the elements of a list.

See also reduce.

R.sum([2,4,6,8,100,1]); //=> 121

modulo

Number → Number → Number

Parameters

• aThe value to the divide.
• bThe pseudo-modulus

Returns Number The result of b % a.

Added in v0.1.1

Divides the first parameter by the second and returns the remainder. Note that this function preserves the JavaScript-style behavior for modulo. For mathematical modulo see mathMod.

See also mathMod.

R.modulo(17, 3); //=> 2
// JS behavior:
R.modulo(-17, 3); //=> -2
R.modulo(17, -3); //=> 2
const isOdd = R.modulo(R.__, 2);
isOdd(42); //=> 0
isOdd(21); //=> 1

mathMod

Number → Number → Number

Parameters

• mThe dividend.
• pthe modulus.

Returns Number The result of b mod a.

Added in v0.3.0

mathMod behaves like the modulo operator should mathematically, unlike the % operator (and by extension, R.modulo). So while -17 % 5 is -2, mathMod(-17, 5) is 3. mathMod requires Integer arguments, and returns NaN when the modulus is zero or negative.

See also modulo.

R.mathMod(-17, 5);  //=> 3
R.mathMod(17, 5);   //=> 2
R.mathMod(17, -5);  //=> NaN
R.mathMod(17, 0);   //=> NaN
R.mathMod(17.2, 5); //=> NaN
R.mathMod(17, 5.3); //=> NaN
const clock = R.mathMod(R.__, 12);
clock(15); //=> 3
clock(24); //=> 0
const seventeenMod = R.mathMod(17);
seventeenMod(3);  //=> 2
seventeenMod(4);  //=> 1
seventeenMod(10); //=> 7

de

Number → Number

Added in v0.9.0

Decrements its argument.

See also inc.

R.dec(42); //=> 41

inc

Number → Number

Added in v0.9.0

Increments its argument.

See also dec.

R.inc(42); //=> 43

negate

Number → Number

Added in v0.9.0

Negates its argument.

R.negate(42); //=> -42

mean

[Number] → Number

Added in v0.14.0

Returns the mean of the given list of numbers.

See also median.

R.mean([2, 7, 9]); //=> 6
R.mean([]); //=> NaN

median

[Number] → Number

Added in v0.14.0

Returns the median of the given list of numbers.

See also mean.

R.median([2, 9, 7]); //=> 7
R.median([7, 2, 10, 9]); //=> 8
R.median([]); //=> NaN