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Articles by Mukul Latiyan
Page 28 of 37
How to compare two arrays for equality in Perl?
In Perl, there are two ways to check if two arrays are equal. We can compare two arrays in Perl with the help of "Storable freeze" function or by creating our own custom function. In this tutorial, we will explore both these approaches with the help of examples. Example 1 Let's first explore the "Storable freeze" code and understand how it works. Consider the code shown below. use Storable qw/freeze/; use strict; $Storable::canonical = 1; my @countriesOne = ('India', 'China', 'Russia', 'USA', 'Germany'); my @countriesTwo = ('India', 'China', 'Russia', 'USA', 'Germany'); my @countriesThree = ...
Read MoreHow to check if a variable has a numeric value in Perl?
Suppose we get a variable at runtime in Perl and we want to check if the value that it contains is numeric or not, then we can use the two approaches shown in this tutorial. We will use two simple examples to demonstrate how it works. Example The most basic approach is to use the length and do keywords and then ignore the warnings. Consider the code shown below for the same. $x = 100; if (length(do { no warnings "numeric"; $x & "" })){ print "x is numeric"; } else { print ...
Read MoreHow to check if a Perl hash already contains a key?
Let's consider a scenario where we would want to know if a Perl hash already contains a key or not. To do so in Perl, we can use the exists() function. In this tutorial, we will explore the exists function with the help of two examples. The exists() Function in Perl In Perl, the exists() function checks whether a particular element exists or not in an array or a hash. If the requested element appears in the input array or hash, this function returns "1", else it returns "0". Example 1 Consider the code shown below. In this example, we ...
Read MoreHow to check if a Perl array contains a particular value?
In Perl, we can check whether an array contains a particular value or not with the help of the "grep" keyword. The grep function in Perl is used to filter the input supplied in the function as a parameter out of the list of items. Similar to Linux, it uses the given input to find the matching value. The grep() Method "grep" is a built-in function in Perl, we can pass our regular expression inside this function. It will check the input for matching values and return a list based on whether the condition is true or false. Syntax As ...
Read MoreHow to break out of a loop in Perl?
In most programming languages, we can use the "break" keyword to break out of any type of loop. In Perl too, we have the "break" keyword available, but the keyword that is used the most to break out of a loop is the "last" keyword. The "last" Statement in Perl The "last" statement is used in Perl loops to exit a loop immediately; it is the equivalent of the "break" statement in C/C++ and Java. In practice, you often use the "last" statement to exit a loop if one of the conditions is met, for example, you find an ...
Read MoreHow to Use Instance Variables in Ruby
In Ruby, there are four different types of variables that we can declare −Local VariablesInstance VariablesClass VariablesGlobal VariablesAn Instance variable has a name that starts with the @ symbol. It should be noted that the contents of an instance variable are only restricted to the object which itself refers to.An important point to note about the instance variable in Ruby is that, even if we have two separate objects that belong to the same class, we are allowed to have different values for their instance variables.Instance Variable Characteristics in RubyBefore checking how to use instance variables in Ruby, let's understand ...
Read MoreDifference between 'include' and 'extend' in Ruby
In Ruby, when we are using the include keyword, we are importing a module code, but we aren't allowed to access the methods of the imported modules with the class directly because it basically gets imported as a subclass for the superclass.On the other hand, when we are using the extend keyword in Ruby, we are importing the module code but the methods are imported as class methods. If we try to access the methods that we imported with the instance of the class, the compiler will throw an error.Now let's use these two keywords in a Ruby code to ...
Read MoreHow to use the "not" keyword in Ruby?
In Ruby, we use the not keyword when we want to get an expression and then invert its Boolean value. In simple words, if an expression evaluates to True, then by using the not keyword, we will get False as the result of the expression.It can be said that the not keyword works like the "!" operator in Ruby, but the only difference between them is that the "!" operator has the highest precedence of all operators and the "not" operator has the lowest.SyntaxHere is the syntax of the not keyword in Rubynot expressionNow, let's take a couple of examples ...
Read MoreHow to use the "defined?" keyword in Ruby?
Ruby provides a special keyword known as defined? that is used to determine if a particular object or data type is defined in Ruby or not.The defined? keyword will return a string describing its expression or argument, if the passed expression or argument is defined. It returns nil if the expression or the argument is not defined in Ruby.SyntaxThe syntax of the defined keyword in Ruby is given belowdefined? variable_nameNow, let's take a couple of examples to demonstrate how to use the defined keyword in Ruby.Example 1Consider the code shown below.# Declare the Variables programming = 2 ruby = programming ...
Read MoreHow to use the 'and' keyword in Ruby?
'and' Keyword in RubyIn Ruby, we use the "and" keyword to return True if both the operands are true, and False if one or more of the operands is false. It should be noted that the and keyword is equivalent to the && logical operator, but it has lower precedence in Ruby.SyntaxThe syntax of the and keyword is shown below.expression1 and expression2Let's use the and keyword in a Ruby code and see how it works.ExampleConsider the code shown below.variable1 = "sunshine" variable2 = "$un$h1ne" # Using and keyword if (variable1 == "sunshine" and variable2 == "$un$h1ne") puts "Learn ...
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