array_walk and anonymous function

Question

I'm trying to apply ucfirst to the words in an array using array_walk and an anonymous function. I want to change the values of the "original" array $fruits . Since I can't use pass by reference, what can you recommend me to achieve that?

<?php

$fruits = array('apple', 'orange', 'banana', 'cherry');

array_walk($fruits, function($a) {
        $fruits = ucfirst($a);
});

var_dump($fruits);

//results

array(4) {
  [0] =>
  string(5) "apple"
  [1] =>
  string(6) "orange"
  [2] =>
  string(6) "banana"
  [3] =>
  string(6) "cherry"
}

Answer 1

在这种情况下， array_map是更好的功能。

$fruits = array_map('ucfirst', $fruits);

Answer 2

array_walk(
    $fruits, 
    function(&$a) {
        $a = ucfirst($a);
    }
);

Answer 3

You could use the foreach loop:

$fruits = array('apple', 'orange', 'banana', 'cherry');

foreach($fruits as $key => $value)
{
    $fruits[$key] = ucfirst($value);
}

Answer 4

$allUpperCase = array_map(function($fruit){
    return ucfirst($fruit);
}, $fruits);