foreach()

The foreach() function is a programming construct that iterates through the elements of a provided table or collection, using a specified callback function to perform operations on each element. During each iteration, the callback function is invoked and passed two parameters: the index (or key) and the value associated with the current element in the table.

Syntax

foreach(table, callback)

• table refers to a data structure, such as an array or list, that contains elements to iterate over.
• callback is a function provided as an argument to the loop, which gets executed for each element in table, typically to perform a specific action or operation on each item.

Example

In this example a table containing the names of fruits is declared, and the foreach() function is used to print each fruit name along with its index in the table.

-- Define a table of fruits
fruits = {"apple", "banana", "cherry", "date", "elderberry"}

-- Define a callback function to print each element with its index
function printFruit(index, value)
    print("Fruit at index " .. index .. ": " .. value)
end

-- Use the `foreach()` function to iterate through the table
table.foreach(fruits, printFruit)

This example results in the following output:

Fruit at index 1: apple
Fruit at index 2: banana
Fruit at index 3: cherry
Fruit at index 4: date
Fruit at index 5: elderberry