PHP删除数组元素与删除重复数组函数

$a=array("red", "green", "blue", "yellow");
count($a); //得到4
unset($a[1]); //删除第二个元素
count($a); //得到3
echo $a[2]; //数组中仅有三个元素,本想得到最后一个元素,但却得到blue,
echo $a[1]; //无值

//array array_splice (array input, int offset [, int length [, array replacement]])
//array_splice()其实是替换数组元素的函数,但如果不加替换值就简单的删除元素.下面是array_splice()的用法:
$b=array("red", "green", "blue", "yellow");
array_splice($a,1,1);

$array1 = array(1 => "www.111com.net", 2 => "菠萝", 4 => "www.111com.net",3 => "香蕉",4 => "芭乐",5 => "www.111com.net",6 => "www.111com.net");

$search_keys = array_keys($array1, "www.111com.net");

foreach($search_keys as $key) {
unset($array1[$key]);
}