php基础 数组 遍历

//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();
//1索引数组
//$arr1=[1,2,3,"abc",1,2,3];
//2关联数组
//$arr2=[
//  "one"  => 1,
//  "two"  => 2,
//  "three"=> 3
//];
//echo $arr2["one"];
//数组方法
//array_push($arr2,"zxc");
//array_pop($arr2);
//count($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
//$arr5 = array_unique($arr1);
//删除数组中的元素
//unset($arr1[0]);
//
//echo "<pre>";
//var_dump($arr2);
//echo count($arr2);
//var_dump(in_array("1111",$arr2));
//var_dump($arr5);
//var_dump($arr1);
//echo "</pre>";


//数组遍历
$arr1 = [1,2,3,4,5,6,7];
$arr2=[
    "one"  => 1,
    "two"  => 2,
    "three"=> 3,
    "four" => 4
];
//for ($i=0;$i<count($arr1);$i++){
//    var_dump($arr1[$i]);
//}
//foreach 遍历
//foreach ($arr2 as $v){
//    var_dump($v);
//}

//foreach ($arr2 as $k=>$v){
//    echo $k;
//    echo "----";
//    echo $v;
//    echo "<br>";
//}

//指针遍历
echo "<pre>";
var_dump(each($arr2)[1]);
echo "</pre>";