CS 170 – INTRO TO
SCIENTIFIC AND
ENGINEERING
PROGRAMMING
Character Arrays
• Numeric arrays ~ double arrays ~ matrices
• Character array or char or strings
• Use the single quote ’ to create basic character arrays
• Example
>> A = ’Dr. X is the teacher’;
>> size(A)
>> class(A)
>> whos
Character Arrays
• How much memory does a character array use?
• Example: Recall that a double array uses 8
bytes/element
>> B = rand(1,19);
>> A = ’Dr. X is the teacher’;
>> size(A)
>> size(B)
>> whos
• So, character arrays only use 2 bytes/element.
Numeric Values of Character Arrays
• A character array = numberic array = integer values
• You can convert a character array into its numeric array
using the command DOUBLE.
• You can convert a double array with integer values into its
equivalent character array using the CHAR command.
>> double([’Class is half over’])
>> v=[98 101 32 112 97 116 105 101 110 116]
>> char(v)
Referencing a CHAR array
• Use integer indices
• Example
>> A = ’Dr. X is the teacher’;
>> A(1:4)
>> A(end:-1:1)
>> A([5 8 12])
Concatenating CHAR arrays
• Use square brackets to stack
• Example
>> str1 = ’Math is fun, ’;
>> str2 = ’but Engineering is better!’;
>> str3 = [str1 str2]
>> size(str1)
>> size(str2)
>> size(str3)
>> str4 = [str1 ; ’ ’ str2];
>> disp(str4)
QUESTIONS??