rest operator in php

 The rest operator (...) in PHP, also known as the variadic parameter, allows you to capture an arbitrary number of arguments into a single array parameter within a function. This is particularly useful when you want to define a function that can accept a variable number of arguments without explicitly specifying each one. Here's an example of how to use the rest operator in PHP:

php
function sum(...$numbers) {
    $total = 0;
    foreach ($numbers as $number) {
        $total += $number;
    }
    return $total;
}

echo sum(1, 2, 3, 4);  // Outputs 10 (1 + 2 + 3 + 4)

In this example:

• The sum function accepts an arbitrary number of arguments using the rest operator ...$numbers.
• Inside the function, $numbers is treated as an array containing all the arguments passed to the function.
• The function then iterates through the array and calculates the sum of all numbers.

You can pass any number of arguments to the sum function, and they will be automatically captured and handled as an array inside the function.

Another common use case for the rest operator is when calling a variadic function with an array of arguments:

php
function multiply($multiplier, ...$numbers) {
    $result = [];
    foreach ($numbers as $number) {
        $result[] = $multiplier * $number;
    }
    return $result;
}

$multiplied = multiply(2, 1, 2, 3, 4);
print_r($multiplied);  // Outputs [2, 4, 6, 8]

Here, the multiply function takes a multiplier as the first argument and then multiplies it with each subsequent argument passed to the function. The rest operator captures all remaining arguments as an array, allowing for flexible function calls with varying numbers of arguments.

The rest operator is a convenient feature in PHP for working with functions that need to handle variable numbers of arguments or arrays of data.