Dependent variable

Also called an outcome variable and response variable, a dependent variable is a variable whose value relies on the outcome of another operation or other variables. For example, a student's GPA (grade point average) is a dependent variable because its value is determined by the averages of all course marks.

In contrast, an independent variable or predictor variable is a variable whose value does not rely on another operation or variable. An example is a person's age because no other input can change someone's age.

Programming a dependent and independent variable

Below is an example Perl script that accepts input from a user, which is considered the independent variable. The "$age" variable is independent in this example.

The output variable, called "$ten" in our example, is dependent because it relies on the input's value.

use strict;
print "\nWhat is your age? ";
my $age = <STDIN>;
if ($age =~ /^[0-9]+$/) {
 $ten = $age + 10;
 print "In ten years, you'll be: $ten, that's old.\n";
}
else {
 print "Invalid age.\n";
}

Running the script above would ask you, "What is your age?" If you entered "44," the script would print, "In ten years, you'll be 54, that's old."

Global variable, Programming terms, Variable