How to use PowerShell “Contains” – A Quick Guide!

The Contains method in PowerShell can be used to check if a specified string or character exists within a string and the PowerShell operator Contains allows you to check if a collection of objects, such as an array, contains a specific value. It returns a Boolean value, either $true if the string or character is found, or $false if it is not found. Here is a detailed guide on how to use the Contains in PowerShell:

How to Use PowerShell “Contains” Function in String?

The PowerShell contains function allows you to check if a string contains a specific substring. This can be useful for finding specific text in a file or checking if a string contains a certain word or phrase. The PowerShell “Contains” function can be used by running the following command:

"Hello world".Contains("world")

In this example, we are checking if the string “Hello world” contains the substring “world”, and it returns “True”.

The Contains operator can be used in conditional statements, such as if statements, to check if a collection contains a specific value and take action based on the result. Here is an example of using the Contains operator in an if statement:

$string = "Hello, World!"
if ($string.Contains("World")) {
    Write-Output "The string contains the word 'World'"
} else {
    Write-Output "The string does not contain the word 'World'"
}

In this example, the Contains method will return $true because the string “Hello, World!” contains the word “World”.

How to use the Contains method for a case-insensitive search?

The contains method is case-sensitive by default! So, the “Hello world”.Contains(“WORLD”) returns False, as the case differs. To perform a case-insensitive check, you can convert and make sure both the string and substring to the same case using ToLower() or ToUpper() methods. E.g

"Hello World".ToUpper().Contains("WORLD")

Using Contains Operator with Arrays

You can also use the -Contains Operator to check if an object is contained in an array or collection. For example:

#Array
$array = "apple", "banana", "mango"

#Check if array contains a string
if ($array -Contains "banana") {
    Write-Output "The array contains the string 'banana'"
} 
else {
    Write-Output "The array does not contain the string 'banana'"
}

In this example, the -Contains operator will return $true because the string “banana” is contained in the array.

Also, The Contains operator does not use strict equality comparison, meaning that it does not check if the value is exactly equal to the value in the collection. For example,

$Array = 1, 2, 3.0, 4, 5
$result = $Array -Contains 3

Write-Output $result

Would return True as the $arrary containing the value 3.0, as the values are equal. The -notcontains can be used to negate the result of the Contains operator.

#array
$Array = 1, 2, 3, 4, 5

#Checks if an array not contains a value
$Result = $Array -NotContains 5

Write-Output $Result

This would return False, as the array contains the given value: 5. If you want to perform a case-sensitive search, use the -CContains operator. E.g.

#Array
$array = "apple", "banana", "mango"

#Check if array contains a string
$Array -CContains "Banana"

This returns False, as the case for “banana” and “Banana” is not the same.

Tail: The “IN” operator vs. Contains in PowerShell

The -in operator checks if the value exists in an array (Whereas the Contains operator checks if an array contains a given value):

#array
$Array = 1, 2, 3, 4, 5

#Checks if a value exists in the Array 
$Result = 4 -in $Array

Write-Output $Result

I hope this helps give you a basic understanding of how to use the Contains method and operator in PowerShell.

Conclusion

In summary, the contains operator or method is a useful tool in PowerShell for checking if a collection of objects, such as an array or a string, contains a specific value. It has a simple syntax and can be used in a variety of situations to automate tasks and make your work more efficient. In this article, we have discussed the PowerShell contains function to check if a string contains a specific substring. We have also learned through some examples how to use this function.