Course of Raku / Essentials / Control flow essentials / Loops

for loops

The for loop is a powerful tool to iterate over multiple elements. For example, let us take a range:

for 1..5 -> $n {
    say $n;
}

In this program, the variable $n takes the next value from the range on each iteration. Notice that you do not have to declare the variable with my explicitly. The block of code is repeated as many times as the number of elements in the data source. So, the program prints the numbers line by line:

$ raku t.raku 
1
2
3
4
5

The program iterates over all the values that the range 1..5 generates. These are 1, 2, 3, 4, and 5.

Taking more than one value

An interesting feature of Raku is that you can take more than one item in a single iteration. The following program prints two number in a loop:

for 1..6 -> $n, $m {
    say "$n and $m";
}

The output of this program is the following:

$ raku t.raku
1 and 2
3 and 4
5 and 6

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