Softanza
StartFrançais
Softanza
StartFrançais
Reference · stzNumber

Subtract()

Same as SubStruct: Subtract the given number from this one (mutating).

Basic examples (2)

Softanza
# 0.1 + 0.2 is 0.3
? (new stzNumber("0.1")).AddQ("0.2").Content()
# 0.1 * 0.1 is 0.01, not 0.0
? (new stzNumber("0.1")).MultiplyByQ("0.1").Content()
# 0.5 * 0.5 is 0.25, not 0.3
? (new stzNumber("0.5")).MultiplyByQ("0.5").Content()
# a price times a rate keeps its cents
? (new stzNumber("19.99")).MultiplyByQ("0.15").Content()
# ...and times a whole number
? (new stzNumber("19.99")).MultiplyByQ(3).Content()
# 0.25 * 0.25 is 0.0625
? (new stzNumber("0.25")).MultiplyByQ("0.25").Content()
# 0.01 * 0.01 is 0.0001
? (new stzNumber("0.01")).MultiplyByQ("0.01").Content()
# 1 + 0.001 is 1.001, not 1.00
? (new stzNumber("1")).AddQ("0.001").Content()
# 0.5 + 0.125 is 0.625, not 0.6
? (new stzNumber("0.5")).AddQ("0.125").Content()
# 10 - 0.001 is 9.999, not 10.00
? (new stzNumber("10")).SubtractQ("0.001").Content()
Output
0.3
0.01
0.25
2.9985
59.97
0.0625
0.0001
1.001
0.625
9.999

run on 2026-10-02 04:23 inside the library at commit 0e72e2e2c; taken from numeric_exactness_narrated.ring(opens in a new tab)

Softanza
oThird = new stzNumber("1/3")
oThird.Add("2/3")
# a third plus two thirds is ONE
? oThird.Content()
# ...exactly
? oThird.IsExact()
# ...and equals the number 1
? oThird.Same(1)
# a third plus a sixth
? (new stzNumber("1/3")).AddQ("1/6").Content()
# a half less a third
? (new stzNumber("1/2")).SubtractQ("1/3").Content()
# two thirds of three quarters
? (new stzNumber("2/3")).MultiplyByQ("3/4").Content()
# a half divided by a quarter is two
? (new stzNumber("1/2")).DivideQ("1/4").Content()
# every one of those is exact
? (new stzNumber("2/3")).MultiplyByQ("3/4").IsExact()
# a third times three is one
? (new stzNumber("1/3")).MultiplyByQ(3).Content()
# ...and adding zero changes nothing
? (new stzNumber("1/3")).AddQ(0).Content()
Output
1
1
1
1/2
1/6
1/2
2
1
1
1/3

run on 2026-10-02 04:23 inside the library at commit 0e72e2e2c; taken from numeric_rationals_narrated.ring(opens in a new tab)

The extensions of this method

Each extension, and whether it exists for this method; an extension that exists combines with the others (FindSTCS).

Extension
Exists
What it adds · The names
Q
yes
does what the method does, then returns the object, so the call can be chained · SubtractQ
QQ
no
chains on the next, more specific type of object (the Q ladder)
QQQ
no
chains on the most specific type of object (the Q ladder)
QRT
no
returns the result as an object of the requested type
CS
no
takes a case-sensitivity flag
ST
no
takes the position to start from (StartingAt)
IB
no
takes bounds that are included (IncludingBounds)
XT
no
the extended form: more parameters than the base method
XTT
no
yet another extension: a further extended form, after XT
Z
no
includes the position in what it returns
ZZ
no
returns positions as sections, [start, end]
W
no
selects by a condition
WF
no
selects by a condition, with the expressive keywords (@NextItem, @PreviousItem...)
D
no
takes a direction, forward or backward (Directional)
F
no
takes a function (the condition or the update is given as a function); the forms document also uses F for the future form, which defers the action
Many
yes
works on a collection of items instead of one (the plural form) · SubtractMany
Except
no
takes exceptions, what to leave out (the exceptional form)
U
no
returns the result without duplication

Every example is a test file of the library, run inside the library for this page; only those whose output kept every promise their file wrote are shown.

See also