index

Definition

Locate the position of a substring.

This generic interface extends the intrinsic Fortran index function to support the fpx string type.

Supported combinations are:

• index(string, string)
• index(string, character(*))
• index(character(*), string)

The optional argument back behaves exactly as in the intrinsic Fortran procedure:

• if absent or .false., the first occurrence is returned;
• if .true., the last occurrence is returned.

The function returns zero if the substring is not found.

Examples

String and character:

type(string) :: s
 
s = 'banana'
 
print *, index(s, 'na')               ! 3
print *, index(s, 'xy')               ! 0

String and string:

type(string) :: text
type(string) :: sub
 
text = 'banana'
sub  = 'na'
 
print *, index(text, sub)             ! 3

Search from the end:

type(string) :: s
 
s = 'banana'
 
print *, index(s, 'na', back=.true.)  ! 5

Mixed usage:

type(string) :: sub
 
sub = 'ana'
 
print *, index('banana', sub)         ! 2

Returns

Position of the matching substring, or zero if not found.

Definition at line 395 of file string.f90.

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The documentation for this interface was generated from the following file:

• string.f90