Precautions from PHP5 to PHP7 (2) some new features of PHP7

Precautions from PHP5 to PHP7 (2) some new features of PHP7

1. define defined constants not only support scalar, but also support arrays

Define ('phpxy', array (
'Fengjie ',
'Sister Furong ',
'Yang mi is dump'
));

Echo PHPXY [1]; // The output is "Sister Furong"
?>

2. supported comparison <=> strings, arrays, and integers.

// Integers
Echo 1 <=> 1; // 0
Echo 1 <=> 2; // 1
Echo 2 <=> 1; // 1

PHP school evaluation: We believe that the actual user base is small and the usage in actual work is not very high.

3. in PHP7, the mandatory parameter type of the function is supported.

// Coercive mode
Function sumOfInts (int... $ ints)
{
Return array_sum ($ ints );
}

Var_dump (sumOfInts (2, '3', 4.1 ));

// 9 is output in this example. why? -- This is mandatory for integer type.

PHP evaluation: function funcName (... parameter) is supported by php5.6. Do not think it is a knowledge point in PHP 7

4. the return type is also mandatory

Function arraysSum (array... $ arrays): array
{
Return array_map (function (array $ array): int {
Return array_sum ($ array );
}, $ Arrays );
}

Print_r (arraysSum ([1, 2, 3], [4, 5, 6], [7, 8, 9]);

5. the call method is created to be called externally. in a shorter way, the anonymous function is appended to the peer and the call is completed.

Class A {private $ x = 1 ;}

// Pre PHP 7 code
$ GetXCB = function () {return $ this> x ;};
$ GetX = $ getXCB> bindTo (new A, 'A'); // intermediate closure
Echo $ getX ();

// PHP 7 + code
$ GetX = function () {return $ this> x ;};
Echo $ getX> call (new );

6. the member method can also specify that a class type must be returned.

Class {}
Class B extends {}

Class C
{
Public function test ():
{
Return new;
}
}