string trim ( string $str [, string $character_mask = " \t\n\r\0\x0B" ] )

mixed str_replace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )

$str1 = str_replace('%name%', 'LargerK', 'my name is %name%');
echo $str1;   // 輸出 my name is LargerK

$str1 = str_replace(['s', 'a', 't'], '111', 'this is an apple');
echo $str1;   // 輸出 111hi111 i111 111n 111pple

$str1 = str_replace(["KFC", "可樂(lè)", "薯?xiàng)l"], ["披薩", "酥皮湯", "西冷牛排"], '我想吃KFC 點(diǎn)個(gè)薯?xiàng)l和可樂(lè)');
echo $str1;   // 我想吃披薩 點(diǎn)個(gè)西冷牛排和酥皮湯

$count = 0;
$str1 = str_replace("oo", "~~", "ooop good... so cool", $count);
echo $str1 . "<br />";   // 輸出~~op g~~d... so c~~l
echo $count;        // 輸出 3

int strlen ( string $string )

echo strlen('hello k');   // 7

array array_diff ( array $array1 , array $array2 [, array $... ] )

$array1 = ['1', 'name' => 'alex k', 'age' => 24, 'desire' => 'Web developer'];
$array2 = ['title' => 'alex k', 'age' => 23, 'desire' => 'Web developer'];
// 需要注意的是,它只匹配value而忽略key
print_r(array_diff($array1, $array2)); // Array ( [0] => 1 [age] => 24 )

array array_slice ( array $array , int $offset [, int $length = NULL [, bool $preserve_keys = false ]] )

$array = ['php', 'html', 'css', 'sql', 'laravel'];
$slice1 = array_slice($array, 1);
$slice2 = array_slice($array, -2);
print_r($slice1);  // Array ( [0] => html [1] => css [2] => sql [3] => laravel )
print_r($slice2);  // Array ( [0] => sql [1] => laravel )

$array = ['php', 'html', 'css', 'sql', 'laravel'];
$slice1 = array_slice($array, 1, 2);
$slice2 = array_slice($array, -2, 1);
print_r($slice1);  // Array ( [0] => html [1] => css )
print_r($slice2);  // Array ( [0] => sql )

$array = ['php', 'html', 'css', 'sql', 'laravel'];
$slice1 = array_slice($array, 1, -1);
$slice2 = array_slice($array, -3, -1);
print_r($slice1);  // Array ( [0] => html [1] => css [2] => sql )
print_r($slice2);  // Array ( [0] => css [1] => sql )

$array = ['php', 'html', 'css', 'sql', 'laravel'];
$slice1 = array_slice($array, 1, -1);
$slice2 = array_slice($array, 1, -1, true);
print_r($slice1);  // Array ( [0] => html [1] => css [2] => sql )
print_r($slice2);  // Array ( [1] => html [2] => css [3] => sql )

array array_unique ( array $array [, int $sort_flags = SORT_STRING ] )

$array = ['a' => 'blue', 'yellow', 'b' => 'black', 'blue', 'c' => 'black'];
$result = array_unique($array);
print_r($result);    // Array ( [a] => blue [0] => yellow [b] => black )