New Features In PHP 7 With Examples

// Coercive mode
function sumOfInts(int ...$ints)
{
    return array_sum($ints);
}
var_dump(sumOfInts(2, '3', 4.1)); // int(9)

But in strict type check, you can only add those variables whom data type are defined in the function. You can on it by adding declare(strict_types=1); at the top of your php code.

For example:

function div(float $x, float $y)
{
    return $x / $y;
}
function sub(int $x, int $y)
{
    return $x - $y;
}
var_dump(div(2, 3.5)); // float(0.57142857142857)
var_dump(sub('2', 3)); // Fatal error: Uncaught TypeError: Argument 1 passed to sub() must be of the type integer, string given

Comparison Operator:

PHP 7 comes with two new comparison operators one is spaceship or Combine Comparison Operator (<=>) and second is Null Coalesce Operator (??).

The benefits of Combine Comparison Operator is that you can use only to compare your values whether they are greater, less or equal. It returns 1 if the value compared is greater, 0 if they are equal and -1 if they are less.

For example:

// compares strings lexically
var_dump('PHP' <=> 'Node'); // int(1)
echo "<br>";
// compares numbers by size
var_dump(305 <=> 456); // int(-1)
echo "<br>";
// compares corresponding array elements with one-another
var_dump(['a', 'b'] <=> ['b', 'c']); // int(0)

The Null Coalesce Operator compare the value whether they are null or not. It is like isset(), which checks whether is it is empty or not. It returns the result of its first operand if it exists and not null, if it is null it checks the second operand. If you have defined many operand for comparison it will check all till it find a result which is not null.

For example:

$x = NULL;
$y = 2;
$z = 3;
var_dump($x ?? $y ?? $z); // result will be int(2)
echo "<br>";

Return Type

// Return Type is Float
function sumOfInts(float ...$ints): float
{
    return array_sum($ints);
}
var_dump(sumOfInts(2, '3', 4.1)); // float(9.1)

define('ALLOWED_IMAGE_EXTENSIONS', ['jpg', 'jpeg', 'gif', 'png']);

function gen()
{
    yield 1;
    yield 2;
    yield from gen2();
    return yield from gen3();
}
function gen2()
{
    yield 3;
    return 4;
}
function gen3()
{
    yield 5;
    return 6;
}
$gen = gen();
foreach ($gen as $val)
{
    echo $val, PHP_EOL;
}
echo $gen->getReturn();
echo "<br>";
echo var_dump($gen);

<?php
class foo {
    function foo() {
        echo 'I am the constructor';
    }
}
?>

<?php
class foo {
    function bar() {
        echo 'I am not static!';
    }
}
foo::bar();
?>

I am not static!