In perl there are two ways to represent string literals: single-quoted strings and double-quoted strings.
Single-Quoted Strings
Single quoted are a sequence of characters that begin and end with a single quote. These quotes are not a part of the string they just mark the beginning and end for the Perl interpreter. If you want a ' inside of your string you need to preclude it with a \ like this \' as you'll see below. Let's see how this works below.
Double-Quoted Strings
Double quoted strings act more like strings in C or C++ the backslash allows you to represent control characters. Another nice feature Double-Quoted strings offers is variable interpolation this substitutes the value of a variable into the string. Some examples are below
Some of the things you can put in a Double-Quoted String
Single-Quoted Strings
Single quoted are a sequence of characters that begin and end with a single quote. These quotes are not a part of the string they just mark the beginning and end for the Perl interpreter. If you want a ' inside of your string you need to preclude it with a \ like this \' as you'll see below. Let's see how this works below.
'four' #has four letters in the string 'can\'t' #has five characters and represents "can't" 'hi\there' #has eight characters and represents"hi\\there" (one \ in the string) 'blah\\blah' #has nine characters and represents "blah\\blah" (one \ in the string)If you want to put a new line in a single-quoted string it goes something like this
'line1 line2' #has eleven characters line1, newline character, and then line2Single-quoted strings don't interpret \n as a newline.
Double-Quoted Strings
Double quoted strings act more like strings in C or C++ the backslash allows you to represent control characters. Another nice feature Double-Quoted strings offers is variable interpolation this substitutes the value of a variable into the string. Some examples are below
$word="hello"; #$word becomes hello $statement="$word world"; #variable interpolation, $statement becomes "hello world" "Hello World\n"; #"Hello World" followed by a newline
Some of the things you can put in a Double-Quoted String
Representation | What it Means |
\a | Bell |
\b | Backspace |
\e | Escape |
\f | Formfeed |
\n | Newline |
\r | Return |
\t | Tab |
\\ | Backslash |
\" | Double quote |
\007 | octal ascii value this time 007 or the bell |
\x07 | hex ascii value this time 007 or the bell |
\cD | any control character.. here it is control-D |
\l | lowercase next letter |
\u | uppercase next letter |
\L | lowercase all letters until \E |
\U | uppercase all letters until \E |
\Q | Backslash quote all nonletters and nonnumbers until \E |
\E | Stop \U \L or \Q |
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