To form string literals that take up more than one line, you can concatenate the two strings. To do this, type a backslash, then press the RETURN key. The backslash causes the compiler to ignore the following newline character. For example, the string literal
"Long strings can be bro\
ken into two or more pieces."
is identical to the string
"Long strings can be broken into two or more pieces."
String concatenation can be used anywhere you might previously have used a backslash followed by a newline character to enter strings longer than one line.
To force a new line within a string literal, enter the newline escape sequence (\n) at the point in the string where you want the line broken, as follows:
"Enter a number between 1 and 100\nOr press Return"
Because strings can start in any column of the source code and long strings can be continued in any column of a succeeding line, you can position strings to enhance source-code readability. In either case, their on-screen representation when output is unaffected. For example:
printf ( "This is the first half of the string, "
"this is the second half ") ;
As long as each part of the string is enclosed in double quotation marks, the parts are concatenated and output as a single string. This concatenation occurs according to the sequence of events during compilation specified by translation phases.
"This is the first half of the string, this is the second half"
A string pointer, initialized as two distinct string literals separated only by white space, is stored as a single string (pointers are discussed in Pointer Declarations in Chapter 3). When properly referenced, as in the following example, the result is identical to the previous example:
char *string = "This is the first half of the string, "
"this is the second half";
printf( "%s" , string ) ;
In translation phase 6, the multibyte-character sequences specified by any sequence of adjacent string literals or adjacent wide-string literals are concatenated into a single multibyte-character sequence. Therefore, do not design programs to allow modification of string literals during execution. The ANSI C standard specifies that the result of modifying a string is undefined.