php 是否具有等效于 javascript 的箭头函数 (=>)？

Question

I know the => symbol is used when constructing arrays in php. But in javascript, you can use the symbol to shorten a function like this:

var materials = [
  'Hydrogen',
  'Helium',
  'Lithium',
  'Beryllium'
];

console.log(materials.map(material => material.length));
// expected output: Array [8, 6, 7, 9]

where material would be the input of the function and material.length the return value.

Is there's an equivalent in php?

Answer 1

In php7.4 arrow functions are implemented according to this rfc https://wiki.php.net/rfc/arrow_functions_v2

Sample here: https://3v4l.org/ddooc , watch the results depending on php version.

$array = ['string1', 'longstring'];
print_r(array_map(fn($x) => strlen($x), $array));

In older versions of php you still have to use:

array_map( 
    function ($x) {
        return strlen($x);
    },
    $array
);