The For loop is also known as a ‘For‘ statement in a PowerShell. This loop executes the statements in a code of block when a specific condition evaluates to True. This loop is mostly used to retrieve the values of an array.
Syntax of For loop
for (<Initialization>; <Condition or Test_expression>; <Repeat>)
{
Statement-1
Statement-2
Statement-N
}In this Syntax, the Initialization placeholder is used to create and initialize the variable with the initial value.
The Condition placeholder in a loop gives the Boolean value True or False. PowerShell evaluates the condition part each time when this loop executes. When it returns a True value, the commands or statements in a command block are executed. The loop executed its block until the condition become false.
The Repeat placeholder in a loop denotes one or more commands which are separated by commas. It is used to modify the value of a variable which is checked inside the Condition part of the loop.
Flowchart of For loop
Examples
Example1: The following example describes how to use a ‘for‘ loop in PowerShell:
for($x=1; $x -lt 10; $x=$x+1)
>> {
>> echo $x
>> }Output:
1
2
3
4
5
6
7
8
9
In this example, the variable $x is initialized to 1. The test expression or condition $x less than 10 is evaluated. Since 1 less than 10 is true, the statement in for loop is executed, which prints the 1 (value of x).
The repeat statement $x=$x+1 is executed. Now, the value of $x will be 2. Again, the test expression is evaluated to true, and the statement in for loop is executed and will print 2 (value of $x). Again, the repeat statement is executed, and the test expression $x -lt 10 is evaluated. This process goes on until $x becomes 9. When the value of x becomes 10, $x < 10 will be false, and the ‘for‘ loop terminates.
Example2: The following example describes the loop which prints the string values of an array in PowerShell:
PS C:\> $arrcolors = "Red","Orange","Green","White","Blue","Indigo","black","Violet"
PS C:\> for($i=0; $i -lt $arrcolors.Length; $i++)
>> {
>> $arrcolors[$i]
>> }Output:
Red
Orange
Green
White
Blue
Indigo
black
Violet
Example3: The following example of for loop displays the same value of variable repeatedly until you press the key: ‘ctrl+C‘ in PowerShell.
PS C:\> $j = 10
PS C:\> for (;;)
>> {
>> echo $j
>> }Output:
10
10
10
10
10
10........................
Example4: The following example prints the even and odd number from 1 to 30 in a table form.
PS C:\> for($i=1;$i -le 30;$i++){
>> if($i -le 1)
>> {
>> echo "Even - Odd"
>>}
>> $res=$i%2
>> if($res -eq 0)
>> {
>> echo " $i "
>> }else
>> {
>> echo " $i"
>> }
>> }Output:
Even - Odd
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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