# MBStrLead (W*S)

NLS Function: Performs a context-sensitive test to determine whether a given character byte in a string is a multibyte-character lead byte.

## Module

USE IFNLS

result = MBStrLead (string,position)

string | (Input) Character*(*). String containing the character byte to be tested for lead status.
position | (Input) INTEGER(4). Position in string of the character byte in the string to be tested.

## Results

The result type is LOGICAL(4). The result is .TRUE. if the character byte in position of string is a lead byte; otherwise, .FALSE..

MBStrLead is passed a whole string and can identify any byte within the string as a lead or trail byte because it performs a context-sensitive test, scanning all the way back to the beginning of a string if necessary to establish context.

MBLead is passed only one character at a time and must start on a lead byte and step through a string one character at a time to establish context for the character. So, MBStrLead can be much slower than MBLead (up to n times slower, where n is the length of the string).

Parent topic: National Language Support (NLS) Library Routines

## See Also

MBLead