YouTipPerl Unless Statement
# Perl UNLESS Statement
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An `unless` statement consists of a boolean expression followed by one or more statements.
### Syntax
The syntax is as follows:
unless(boolean_expression){ # Executes when the boolean_expression is false}
If the boolean_expression evaluates to `false`, the code block inside the `if` statement will be executed. If the boolean_expression evaluates to `true`, the first set of code after the `if` statement (after the closing brace) will be executed.
### Flowchart
!(#)
## Example
#!/usr/bin/perl$a = 20; # Use unless statement to check boolean expression unless($a<20){# Executes when the boolean expression is false printf"a is greater than or equal to 20n"; }print"The value of a is: $an"; $a = ""; # Use unless statement to check boolean expression unless($a){# Executes when the boolean expression is false printf"Condition a is falsen"; }print"The value of a is: $an";
Executing the above program produces the following output:
a is greater than or equal to 20 The value of a is: 20Condition a is false The value of a is:
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