isletter

Determine which characters are letters

Syntax

TF = isletter(A)

Description

TF = isletter(A) returns a logical array TF. If A is a character array or string scalar, then the elements of TF are logical 1 (true) where the corresponding characters in A are letters, and logical 0 (false) elsewhere.

If A is not a character array or string scalar, then isletter returns logical 0 (false).

Examples

Determine Which Character Array Elements Are Letters

Create different arrays, and then determine which array elements are letters.

chr = '123 Main St.'

chr = 
'123 Main St.'

TF = isletter(chr)

TF = 1x12 logical array

   0   0   0   0   1   1   1   1   0   1   1   0

Convert chr to a string, and test it. The input argument is not a character array, so isletter returns 0.

str = string(chr)

str = 
"123 Main St."

TF = isletter(str)

TF = 1x12 logical array

   0   0   0   0   1   1   1   1   0   1   1   0

Input Arguments

A — Input array

scalar | vector | matrix | multidimensional array

Input array, specified as a scalar, vector, matrix, or multidimensional array. A can be any data type.

Tips

To find letters within elements of a nonscalar string array, use the isstrprop function.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• Input values from the char class must be in the range 0-127.

Thread-Based Environment
Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

Version History

Introduced before R2006a