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Converting from String to Numeric

Function Summary

The functions listed in this table provide a number of ways to convert character strings to numeric data.

Function

Description

Example

uintN (e.g., uint8)

Convert a character to an integer code that represents that character.

'Hi'72 105

str2num

Convert a character type to a numeric type.

'72 105'[72 105]

str2double

Similar to str2num, but offers better performance and works with cell arrays of strings.

{'72' '105'} [72 105]

hex2num

Convert a numeric type to a character type of specified precision, returning a string that MATLAB® can evaluate.

'A''-1.4917e-154'

hex2dec

Convert a character type of hexadecimal base to a positive integer.

'A'10

bin2dec

Convert a positive integer to a character type of binary base.

'1010'10

base2dec

Convert a positive integer to a character type of any base from 2 through 36.

'12'10 (if base == 8)

Converting from a Character Equivalent

Character arrays store each character as a 16-bit numeric value. Use one of the integer conversion functions (e.g., uint8) or the double function to convert strings to their numeric values, and char to revert to character representation:

name = 'Thomas R. Lee';

name = double(name)
name =
    84  104  111  109  97  115  32  82  46  32  76  101  101

name = char(name)
name =
   Thomas R. Lee

Converting from a Numeric String

Use str2num to convert a character array to the numeric value represented by that string:

str = '37.294e-1';

val = str2num(str)
val =
    3.7294

The str2double function converts a cell array of strings to the double-precision values represented by the strings:

c = {'37.294e-1'; '-58.375'; '13.796'};

d = str2double(c)
d =
    3.7294
  -58.3750
   13.7960

whos
  Name      Size                   Bytes  Class

  c         3x1                      224  cell
  d         3x1                       24  double

Converting from a Specific Radix

To convert from a character representation of a nondecimal number to the value of that number, use one of these functions: hex2num, hex2dec, bin2dec, or base2dec.

The hex2num and hex2dec functions both take hexadecimal (base 16) inputs, but hex2num returns the IEEE® double-precision floating-point number it represents, while hex2dec converts to a decimal integer.

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