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Programming-Idioms

  • Java
  • Fortran
  • Go
  • Ruby

Idiom #341 Find substring last position

Set i to the position of the last occurrence of the string y inside the string x, if exists.

Specify if i should be regarded as a character index or as a byte index.

Explain the behavior when y is not contained in x.

i = x.rindex(y)

i is a character index. Returns nil if y is not present in x.
int i = x.lastIndexOf(y);

This will return the index of the first `char` of y in x, or -1 if it's not found.
import "strings"
i := strings.LastIndex(x, y)

i is the byte index of y in x, not the character (rune) index.

i will be -1 if y is not found in x.
StrUtils
i := RPos(y,x);

The index is byte-based.
A return value of zero indicates the substring was not found.
New implementation...
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programming-idioms.org 
i = x.rindex(y)
int i = x.lastIndexOf(y);
i := strings.LastIndex(x, y)
i := RPos(y,x);
i = x.rfind(y)
let i = x.rfind(y);