Package variables are global in scope and are available throughout the entire program. Perl has three levels of variable scoping: package, lexical (or block), and dynamic scoping. The third if statement matches the pattern /^The/, which looks for the string "The" at the beginning of the $string variable. The second if statement matches the pattern /fox|dog/, which looks for either "fox" or "dog" in the $string variable. The first if statement matches the pattern /brown/, which looks for the string "brown" anywhere in the $string variable. In this example, the =~ operator is used to match regular expressions against the $string variable. Print "Found 'fox' or 'dog' in the string!\n" Here's an example of regular expression matching in Perl: my $string = "The quick brown fox jumps over the lazy dog" Regular expressions are a powerful tool for text processing and allow you to match complex patterns in text data. Regular expression matching in Perl is the process of searching for patterns within strings using regular expressions. The given/ when control structure checks the value of a variable and executes a block of code based on the value. The for loop and foreach loop both iterate over an array and print its elements. The while and until loops both print the value of a variable until a certain condition is met. In this example, the if/ else control structure checks if $age is greater than or equal to 18 and prints a different message depending on the result. Here's an example of each type of control structure: # if/else There are several types of control structures in Perl, including if/ else, while/ until, for/ foreach, and given/ when. The print statement uses interpolation to output the value of $sum, which will output "The sum of 10 and 5 is 15." to the console.Ĭontrol structures in Perl are used to change the flow of execution of a program based on certain conditions. The variable $sum is then assigned the result of adding $x and $y, which is 15. In this example, the variables $x and $y are declared and initialized to the numbers 10 and 5, respectively. Scalar variables can also be used to store numbers and perform arithmetic operations: my $x = 10 The print statement uses double quotes to interpolate the value of $name into the string "My name is $name.", which will output "My name is John." to the console. In this example, the variable $name is declared and initialized to the string "John". Here's an example of declaring and using a scalar variable to store a string: my $name = "John" They are declared using the dollar sign ( $) followed by the variable name. In Perl, scalar variables are used to store a single value, such as a number or a string.
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