What are arrays in Perl?
An array is an ordered and mutable list of scalars. In Perl, scalars are defined as a single unit of data such as an integer, a floating-point, a character, a string, and so on. They are preceded by a ＄ when defined.
Syntax
The array variable begins with an @ sign. We can declare an array in the following way:
@names = ("Jacob", "Kumar", "Dinesh");
Perl does not require us to declare a variable before using it. So, we can directly store the value in it.
Accessing elements
We can access the elements in the array by indexing which works in the following way:
@order_nums = (1, 3, 55);@names = ("Jacob", "Kumar", "Dinesh");print "\$order_nums[0] = $order_nums[0]\n";print "\$order_nums[1] = $order_nums[1]\n";print "\$order_nums[2] = $order_nums[2]\n";print "\$names[0] = $names[0]\n";print "\$names[1] = $names[1]\n";print "\$names[2] = $names[2]\n";
We use the
＄sign to access elements of the array since the element is a scalar variable.
Sequential number arrays
Perl provides a shortcut to define sequential arrays consisting of numbers and letters. Rather than typing to 100, we can use the ... notation as follows:
@range_100 = (1..100);@range_abc = (a...g);print "@range_100\n";print "@range_abc\n";
Array size
The size of an array can be computed using the scalar context on the array. We can see this here:
@range_100 = (1..100);print "Size: ",scalar @range_100,"\n";
Insertion and removal of array elements
We can insert and remove elements from an array by using the following methods:
| Operation | Description |
|---|---|
push |
It adds the element at the end of the array. |
pop |
Removes and returns the last element of the array. |
shift |
Removes and returns the first element of the array with shifting the remaining array. |
unshift |
Adds a new element at the beginning of the array and returns the size of the resulting array. |
Let us execute these operations in the following example:
@cars = ("Honda","Toyota","Hyundai");print "1. \@cars = @cars\n";# pushing an elementpush(@cars, "Tesla");print "2. \@cars after push = @cars\n";# adding an element at beginning of the arrayunshift(@cars, "Ford");print "3. \@cars after unshift = @cars\n";# popping an element.pop(@cars);print "4. \@cars after popping = @cars\n";# removing an element from the beginning of the array.shift(@cars);print "5. \@cars after shift = @cars\n";
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