MATLAB by rudra pratap

3.3 Character strings 79
howdy = [' Hiuuuuu ' ; 'Hellouu ' ; 'Namaste']
with each string being seven characters long (u denotes a space) .
An easier way of doing the same thing is to use the command char, which
converts strings to a matrix. char (s1, s2, . . .) puts each string argument s1, s2 ,
etc., in a row and creates a string matrix by padding Pach row with the appropriate
number of blanks. Thus , to create the same howdy as previously, we type
howdy = char('Hi', 'Hello' , 'Namaste ').
You can also use strvcat functions to create string arrays from string arguments.
However, char is the best function for this purpose.
Because the same quote character (the single right quote) is used to signal the
beginning as well as the end of a string, this character cannot be used inside a
string for a quote or apostrophe. For a quote within a string you must use two
single quotes, ''. Thus, to title a graph with 3-D View of Boomerang 's Path, you
write title ('3-D View of Boomerang ' ' s Path').
3.3.1 Manipulating character strings
Character strings can be manipulated just like matrices. Thus,
c = [howdy(2,:) names (3 , : )]
produces Hello Mary as the output for c. This feature can be used along with
number-to-string conversion functions, such as num2str and int2str , to create text
objects containing dynamic values of variables. Such text objects are particularly
useful in creating titles for figures and other graphics annotation commands (see
Chapter 6). For example, suppose you want to produce a few variance-study graphs
with different values of the sample size n, an integer variable. Producing the title
of the graph with the command
title(['Variance study with sample size n = ',int2str(n) ])
writes titles with the current value of n printed in the title.
There are several built-in functions for character string manipulation:
char
abs
blanks(n)
de blank
eval
findstr
int2str
is char
isletter
lower
mat2str
num2str
strcmp
strncmp
strcat
strvcat
upper
creates character arrays using automatic padding,
also, converts ASCII numeric values to character arrays,
converts characters to their ASCII numeric values,
creates n blank characters,
removes the trailing blanks from a string,
executes the string as a command (see Section 3.3.2) ,
finds the specified substring in a given string,
converts integers to strings (see example given earleir) ,
true ( = 1) for character arrays,
true ( = 1) for alphabetical characters,
converts any uppercase letters in the string to lowercase,
converts a matrix to a string,
converts numbers to strings (similar to int2str) ,
compares two strings, returns 1 if same,
compares the first n characters in given strings,
concatenates strings horizontally, ignoring trailing blanks,
concatenates strings vertically, ignoring empty strings, and
converts any lowercase letters in the string to uppercase.