Number API Functions

This document lists most useful (and most often needed) functions. Be aware, that there are many more to be found in either the class references or via the builtin class browser.

Reference: Integer Float Fraction FixedPoint Complex which all inherit from Number

Back to Useful API Functions

Literals (i.e. Constant Numbers)

1234
16rFFAA or 0xaffe
2r0101 or 0b101010
NrXXX

integer constant; decimal, hex, binary or any base N; integers may be arbitrary long

0.5
1e5
-1.2e-3

float constant; actually double precision; use "q" for extra precision

(4/3)

a fraction (numerator / denominator)

(4+3i)

complex number (real part / imaginary part)

Testing

aNumber isFinite => Boolean

Check if number is not infinity and not NaN:

aNumber isInfinite => Boolean

Check if number is either positive infinity (INF) or negative infinity (-INF):

aNumber isNaN => Boolean

Check if number is NaN ("Not a Number"):

aNumber negative => Boolean

same as aNumber < 0

aNumber positive => Boolean

same as aNumber >= 0

aNumber strictlyPositive => Boolean

same as aNumber > 0

anInteger isPrime => Boolean

true if the number is a prime number

anInteger isPowerOf2 => Boolean

true if there exists an n, such that 2ˆn equals the number

anInteger isPowerOf:b => Boolean

true if there exists an n, such that bˆn equals the number

anInteger nextPrime => anInteger
anInteger nextPowerOf2 => anInteger

Arithmetic

The usual arithmetic operators.
Notice, that they are evaluated left to right, without special precedences. Thus you should always use parentheses to group expressions when there are two or more operators in an arithmetic expression.

aNumber + aNumber  => Number
aNumber - aNumber  => Number
aNumber * aNumber  => Number
aNumber / aNumber  => Number

Truncated result (towards the next smaller integer i.e. towards negative infinity):

aNumber // aNumber  => Integer

Examples:

 100 // 3
 => 33

 -100 // 3
 => -34

Trigonometric and Mathematical Functions

The usual operations are provided as unary messages to the number:

aNumber sin => Number
aNumber log => Number

Printing

Numbers can print themself on an output stream,

aNumber printOn: aStream

or convert themself to a string:

aNumber printString => String

The above generate a standard format, which should fit most needs. More control is available via the printf functions, which offer a range of options to fill left or right, to control printing of the sign and to fill with zeros.
The printf:on: function:

formatString printf: { aNumber } on: aStream

takes an argument Vector as first Argument; thus, multiple values are printed as in the following example:

'%04x %3d %+4.3f\n' printf:{ 123 . 4 . 3.14159 } on:Transcript

Individual conversions can be done with:

aNumber printfPrintString: formatString => String

Notice that printf accepts C-style character escapes (which is not the case in general with Smalltalk)

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