FindFirst()

The first occurrence of the substring: the position(s).

also written: FirstOccurrence · FindFirstSubString · FindFirstOccurrence

Basic examples (2)

Softanza

o1 = new stzString("12*45*78*90")
# the 2nd star from 4
? o1.FindNthST(2, "*", :StartingAt = 4)
# the first star from 4
? o1.FindFirstST("*", :StartingAt = 4)

Output

9
6

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 555_findnthst.ring(opens in a new tab)

Softanza

o1 = new stzString("12*♥*56*♥*")
# the pair spelling
? o1.FindFirstXT("♥", :BoundedBy = [ "*", "*"])
# the string spelling
? o1.FindFirstXT("♥", :BoundedBy = "*")

Output

4
4

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 564_findfirstxt.ring(opens in a new tab)

Scope (7)

Softanza

o1 = new stzString("12♥♥♥67♥♥♥12♥♥♥")
# the 2nd from 3
? o1.FindNthST(2, "♥♥♥", :StartingAt = 3)
# the first from 5
? o1.FindFirstST("♥♥♥", :StartingAt = 5)
# the last from 6
? o1.FindLastST("♥♥♥", :StartingAt = 6)

Output

8
8
13

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 317_using_st_and_std_extension.ring(opens in a new tab)

Softanza

o1 = new stzString("12♥♥♥67♥♥♥12♥♥♥")
# the first from 6
? o1.FindFirstST("♥♥♥", :StartingAt = 6)
# the last from 6
? o1.FindLastST("♥♥♥", :StartingAt = 6)
# the 2nd from 6
? o1.FindNthST(2, "♥♥♥", :StartingAt = 6)

Output

8
13
13

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 323_findfirstst.ring(opens in a new tab)

Softanza

o1 = new stzString("bla {♥♥♥} blaba bla {♥♥♥} blabla")
# the first from 8
? o1.FindFirstST("♥♥♥", :StartingAt = 8)
# the last from 8
? o1.FindLastST("♥♥♥", :Startingat = 8)
# the 2nd from 3
? o1.FindNthST(2, "♥♥♥", :StartingAt = 3)

Output

22
22
22

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 351_findfirstst.ring(opens in a new tab)

Softanza

o1 = new stzString("12♥♥♥67♥♥♥12♥♥♥")
# the first backward from 12
? o1.FindFirstSTD("♥♥♥", :StartingAt = 12, :Backward)
# the last backward from 12
? o1.FindLastSTD("♥♥♥", :StartingAt = 12, :Backward)
# the 2nd backward from 12
? o1.FindNthSTD(2, "♥♥♥", :StartingAt = 12, :Backward)

Output

8
3
3

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 325_findfirststd.ring(opens in a new tab)

Softanza

o1 = new stzString("12♥♥♥67♥♥♥12♥♥♥")
# the 2nd backward from 10 (:Going spelling)
? o1.FindNthSTD(2, "♥♥♥", :StartingAt = 10, :Going = :Backward)
# the first backward from 14 (bare :Backward)
? o1.FindFirstSTD("♥♥♥", :StartingAt = 14, :Backward)
# the last backward from 6 (:Direction spelling)
? o1.FindLastSTD("♥♥♥", :StartingAt = 6, :Direction = :Backward)

Output

3
8
3

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 317_using_st_and_std_extension.ring(opens in a new tab)

Softanza

oAB  = new stzString("ab")
big  = new stzString( oAB.Repeated(1000000) )
# NumberOfChars is 2,000,000
? big.NumberOfChars()
# Contains 'ab' is TRUE
? big.Contains("ab")
# FindFirst 'ab' is 1
? big.FindFirst("ab")
# FindLast 'ab' is 1,999,999
? big.FindLast("ab")

Output

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 999_engine_string_millions_narrated.ring(opens in a new tab)

Softanza

o1 = new stzString("ab_cd_ef_gh")
# the first underscore
? o1.FindFirst("_")
# a missing star from 4
? o1.FindFirstST("*", :StartingAt = 4)
# the underscore from 3
? o1.FindFirstST("_", :StartingAt = 3)
# the last underscore
? o1.FindLast("_")
# no last star
? o1.FindLast("*")
# the 2nd underscore
? o1.FindNth(2, "_")

Output

run on 2026-10-02 04:24 inside the library at commit 0e72e2e2c; taken from 508_findfirst.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

does what the method does, then returns the object, so the call can be chained

chains on the next, more specific type of object (the Q ladder)

QQQ

chains on the most specific type of object (the Q ladder)

QRT

returns the result as an object of the requested type

yes

takes a case-sensitivity flag · FindFirstCS, FindFirstSTCS

yes

takes the position to start from (StartingAt) · FindFirstST, FindFirstSTD, FindFirstSTCS, FindFirstSTZZ and 1 more

takes bounds that are included (IncludingBounds)

yes

the extended form: more parameters than the base method · FindFirstXT

XTT

yet another extension: a further extended form, after XT

yes

includes the position in what it returns · FindFirstZ

yes

returns positions as sections, [start, end] · FindFirstZZ, FindFirstDZZ, FindFirstSTZZ, FindFirstSTDZZ

selects by a condition

selects by a condition, with the expressive keywords (@NextItem, @PreviousItem...)

yes

takes a direction, forward or backward (Directional) · FindFirstD, FindFirstDZZ, FindFirstSTD, FindFirstSTDZZ

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

works on a collection of items instead of one (the plural form)

Except

takes exceptions, what to leave out (the exceptional form)

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.

FindFirst()

Basic examples (2)

Scope (7)

The extensions of this method

See also