Perl | eq operator

Perl | exists() Function

Last Updated : 07 May, 2019

The exists() function in Perl is used to check whether an element in an given array or hash exists or not. This function returns 1 if the desired element is present in the given array or hash else returns 0.

Syntax: exists(Expression)

Parameters:
Expression : This expression is either array or hash on which exists function is to be called.

Returns: 1 if the desired element is present in the given array or hash else returns 0.

Example 1: This example uses exists() function over an array.

#!/usr/bin/perl  
  
# Initialising an array 
@Array = (10, 20, 30, 40, 50); 
  
# Calling the for() loop over 
# each element of the Array 
# using index of the elements 
for ($i = 0; $i < 10; $i++) 
{ 
      
    # Calling the exists() function 
    # using index of the array elements 
    # as the parameter 
    if(exists($Array[$i])) 
    { 
        print "Exists\n"; 
    } 
    else
    { 
        print "Not Exists\n"
    } 
} 

Output:

Exists
Exists
Exists
Exists
Exists
Not Exists
Not Exists
Not Exists
Not Exists
Not Exists

In the above code, it can be seen that parameter of the exists() function is the index of each element of the given array and hence till index 4 (index starts from 0) it gives output as “Exists” and later gives “Not Exists” because index gets out of the array.

Example 2: This example uses exists() function over a hash.

#!/usr/bin/perl  
  
# Initialising a Hash 
%Hash = (Mumbai => 1, Kolkata => 2, Delhi => 3); 
  
# Calling the exists() function 
if(exists($Hash{Mumbai})) 
{ 
    print "Exists\n"; 
} 
else
{ 
    print "Not Exists\n"
} 
  
# Calling the exists() function 
# with different parameter 
if(exists($Hash{patna})) 
{ 
    print "Exists\n"; 
} 
else
{ 
    print "Not Exists\n"
} 

Output :

Exists
Not Exists

In the above code, exists() function takes the key of the given hash as the parameter and check whether it is present or not.

Perl | eq operator

K

Kanchan_Ray

Improve

Article Tags :

Similar Reads

Perl | abs() function

This function returns the absolute value of its argument. If a pure integer value is passed then it will return it as it is, but if a string is passed then it will return zero. If VALUE is omitted then it uses $_ Syntax: abs(VALUE) Parameter: VALUE: It is a required number which can be either positi

Perl | defined() Function

Defined() in Perl returns true if the provided variable 'VAR' has a value other than the undef value, or it checks the value of $_ if VAR is not specified. This can be used with many functions to detect for the failure of operation since they return undef if there was a problem. If VAR is a function

Perl | grep() Function

The grep() function in Perl used to extract any element from the given array which evaluates the true value for the given regular expression. Syntax: grep(Expression, @Array) Parameters: Expression : It is the regular expression which is used to run on each elements of the given array.@Array : It is

Perl | wantarray() Function

wantarray() function in Perl returns True if the currently executing subroutine expects to return a list value, and false if it is looking for a scalar value. Syntax: wantarray() Returns: true for list value and false for scalar values Example 1: #!/usr/bin/perl -w # Subroutine to call wantarray() f

Perl | eq operator

'eq' operator in Perl is one of the string comparison operators used to check for the equality of the two strings. It is used to check if the string to its left is stringwise equal to the string to its right. Syntax: String1 eq String2 Returns: 1 if left argument is equal to the right argument Examp

Perl | Math::BigInt->is_odd() method

Math::BigInt module in Perl provides objects that represent integers with arbitrary precision and overloaded arithmetical operators. is_odd() method of Math::BigInt module is used to check whether a number stored as BigInt object is an odd number or not. Syntax: Math::BigInt->is_odd() Parameter:

Perl | File Test Operators

File Test Operators in Perl are the logical operators which return True or False values. There are many operators in Perl that you can use to test various different aspects of a file. For example, to check for the existence of a file -e operator is used. Or, it can be checked if a file can be writte

Checking the Given File Exists or Not in Golang

In Go language, you are allowed to check whether the given file exists or not with the help of the IsNotExist() function. If this function returns true, then it indicates that the error is known to report that the specified file or directory already does not exist and if it returns false, then it in

strings.ContainsAny() Function in Golang with Examples

ContainsAny function is used to check whether any Unicode code points in chars are present in the string. It is an inbuilt function used to find if a specified string exists in the string if found it will return true or else false. Syntax: func ContainsAny(str, charstr string) bool Here, the first p

strings.ContainsRune() Function in Golang with Examples

The Unicode, which is a superset of ASCII and contains all the characters present in the world's writing system, is the character set that's being followed right now. Each character in the Unicode system is uniquely identified by a Unicode code point, which is referred to as runes in Golang. To know