Describes the arithmetic operators for performing four arithmetic operations in Perl.
Use addition operator "+" to add.
# Addition my $add = 1 + 1;
Use subtraction operator "-" to do the subtraction.
# Subtraction my $sub = 9 - 1;
To do the multiplication, use multiplication operator "*".
# Multiplication my $multi = 5 * 4;
Use division operator "/" to perform the division.
# Division my $div = 9/4;
The answer to division is a decimal if it is not divisible.
Four rules of operation with a simple description
If you want to perform 4 rules on yourself, there is a simple description method.
# Same as $add = $add + 3 $add += 3; # Same as $sub = $sub -5 $sub-= 5; # Same as $multi = $multi * 2 $multi *= 2; # Same as $div = $div/7 $div/= 7;
Seeking quotient and remainder
There is no operator to find the quotient. After dividing with the/operator, the int function retrieves the integer part.
# Quotient my $div_int = int(9/4);
To find the remainder, use modulo operator.
# Remainder my $mod = 9% 4;
Use the ** operator to find the power.
my $two_power_num = 4 ** 2;
Use exponentiation operator "**" to find the exponentiation. Exponentiation is an operation that multiplies the same number multiple times.
Increment and decrement operators
# Increment $num ++; # Decrement $num- ;
There are two ways to write increments and decrements, depending on whether you put ++ or-before or after the variable. Note that the meaning changes depending on the context, depending on whether the operator is added before or after the variable.
my $i = 0; my $k = ++ $i;
my $i = 0; my $k = $i++;
The above two have different values in $k. In the first case, $k contains 1. In the second case, $k will be 0.
If you put ++ before, $i is added 1 before the assignment, and if you put ++ after it, 1 is added to $i after the assignment.
I explained in the case of assignment, but I will also give an example of passing a value to a function.
# The argument of func is $i plus one. func (++ $i); # $I is passed to the argument of func, and then 1 is added. func ($i++);
Numeric automatic expansion
Perl does not have a numeric type in programming languages, but it does have a numeric type internally.
If it cannot be calculated with a 32-bit integer, it will be extended to a 64-bit integer and calculated if the environment supports it.
If it cannot be represented by a 64-bit integer, it will be expanded to a double-precision floating-point type and calculated.
Addition of strings can be done as it is
Perl automatically converts strings to numbers, and even strings can be added with the addition operator if they contain numbers. You can add.
my $num_str1 = "34"; my $num_str2 = "56"; my $total = $num_str1 + $num_str2;
Perl is extremely useful for small tasks because you can get a string containing numbers from a text file and add it as is.
This is an example program for numerical calculation.
Four arithmetic operations
Examples of addition, subtraction, multiplication, and division.
use strict; use warnings; print "(1) 4 rules operation\n"; # Addition my $add = 1 + 1; # Subtraction my $sub = 9 - 1; # Multiplication my $multi = 5 * 4; # Division my $div = 9/4; print "\$add = $add\n"; print "\$sub = $sub\n"; print "\$multi = $multi\n"; print "\$div = $div\n\n"; print "(2) Four-rule operation with a simple description\n"; # Same as $add = $add + 3 $add += 3; # Same as $sub = $sub -5 $sub-= 5; # Same as $multi = $multi * 2 $multi *= 2; # Same as $div = $div/7 $div/= 7; print "\$add = $add\n"; print "\$sub = $sub\n"; print "\$multi = $multi\n"; print "\$div = $div\n\n"; print "(3) Operation to find quotient and remainder\n"; # Quotient my $div_int = int(9/4); # Remainder my $mod = 9% 4; print "\$div_int = $div_int\n"; print "\$mod = $mod\n";
This is an example to find the power.
use strict; use warnings; # Find a power. print "1: Find the power.\n"; my $num = 4; my $two_power_num = 4 ** 2; print "The square of $num is $two_power_num.\n";
Increment and decrement
This is an example using the increment operator and the decrement operator.
use strict; use warnings; # 1 is added before being evaluated. print "(1) Prefix increment and decrement\n"; my $i = 0; print ++ $i . "\n"; print $i . "\n"; print-$i . "\n"; print $i . "\n"; # 1 is added after being evaluated. print "(2) Post-increment and decrement\n"; $i = 0; print $i++ . "\n"; print $i . "\n"; print $i- . "\n"; print $i;