PHP基础（一） 数组

/*123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789123456789*///(按Alt可选多行，加内容……)

//参数默认值function abc($a,$b,$c = 0){    echo $a,$b,$c;}abc(1,3);

//可变参数function def(){    $arr = func_get_args();    var_dump($arr);}echo "<pre>";def(1,2,3,4,5,6);echo "</pre>";

//数组定义$arr1 = [];$arr2 = array();//索引数组$arr1 =[1,2,3,"abc"];

//关联数组$arr2 = [    "one" => 1,    "two" => 2,    "three" =>3 ];echo $arr2["one"];

//数组方法//推array_push($arr2,"xyz");//弹array_pop($arr2);//长度count($arr2);//判断数组中是否存在某个值in_array("1",$arr2);//数组合并$arr3 = array_merge($arr1,$arr2);//数组反转$arr4 = array_reverse($arr2);//数组去重$str5 = array_unique($arr1);//删除数组中的元素unset($arr1[0]);//重置reset($arr1);

//echo "<pre>";//var_dump($arr2);//echo count($arr2);//var_dump(in_array("111",$arr2));//var_dump($arr5)

//echo "</pre>";

//数组遍历//(先定义一波)$arr6 = [1,2,3,4,5,6,7];$arr7 = [    "one"   => 1,    "two"   => 2,    "three" => 3,    "four"  => 4];//1、for循环echo "<br>";for ($i = 0;$i <count($arr6);$i++){    var_dump($arr6[$i]);}

//2、foreach 遍历foreach ($arr7 as $v){    var_dump($v);}foreach ($arr7 as $key=>$value){    echo $key;    echo "______";    echo $value;    echo "<br>";}

//指针遍历echo "<pre>";var_dump(each($arr7));echo "</pre>";