FOR EACH Loop

The FOR EACH loop in ApLang is used to iterate over the elements of a list. This type of loop is ideal when you want to perform an operation on each element of a list without manually managing loop counters or indices. The FOR EACH loop simplifies code that processes each item in a collection, making your programs easier to read and maintain.

Syntax

FOR EACH item IN list {
    // Code to execute for each item
}

• item represents the current element in the list for each iteration of the loop.
• list is the collection of elements you want to iterate over.

Example: Basic FOR EACH Loop

// Define a list of numbers
numbers <- [1, 2, 3, 4, 5]

// Iterate over each number in the list and display it
FOR EACH number IN numbers {
    DISPLAY(number)
}
// Output:
// 1
// 2
// 3
// 4
// 5

In this example, the FOR EACH loop iterates over each element in the numbers list and displays it. The loop executes once for each element in the list.

Example: Performing Operations on List Elements

// Define a list of words
words <- ["apple", "banana", "cherry"]

// Iterate over each word in the list and display it in uppercase
FOR EACH word IN words {
    DISPLAY(word + " in uppercase is " + TO_UPPER(word) + "!")
}
// Output:
// apple in uppercase is APPLE!
// banana in uppercase is BANANA!
// cherry in uppercase is CHERRY!

In this example, the FOR EACH loop iterates over the words list and displays each word, demonstrating how to concatenate strings within the loop.

Example: Modifying Elements Within the Loop

// Define a list of numbers
numbers <- [1, 2, 3, 4, 5]

// Initialize an empty list to hold doubled values
doubled_numbers <- []

// Iterate over each number in the list, double it, and add it to the new list
FOR EACH number IN numbers {
    doubled_numbers <- doubled_numbers + [number * 2]
}

DISPLAY(doubled_numbers)
// Output: [2, 4, 6, 8, 10]

In this example, the FOR EACH loop doubles each number in the numbers list and appends the result to a new list called doubled_numbers. The loop efficiently processes each element and builds a new list of doubled values.

Nesting FOR EACH Loops

You can nest FOR EACH loops to iterate over multiple lists or to perform more complex operations on lists of lists.

// Define a list of lists
matrix <- [[1, 2], [3, 4], [5, 6]]

// Iterate over each row in the matrix
FOR EACH row IN matrix {
    // Iterate over each element in the current row
    FOR EACH element IN row {
        DISPLAY(element)
    }
}
// Output:
// 1
// 2
// 3
// 4
// 5
// 6

In this example, the outer FOR EACH loop iterates over each row of the matrix, and the inner FOR EACH loop iterates over each element in the current row, displaying all elements in the matrix.

Conclusion

The FOR EACH loop is a powerful and versatile tool in ApLang, allowing you to iterate over lists and perform operations on each element with ease. By using FOR EACH loops, you can write cleaner and more efficient code, especially when working with collections of data. Mastering this loop will enable you to handle a wide range of programming tasks involving lists in ApLang.