php数组

使用array() 函数创建数组

php的三种数组类型

1. 索引数组 : 带有数字索引的数组

//索引从0开始
$animal=array("Dog","Cat","Tiger");
$animal2=array();

$animal2[0]="Lion";
$animal2[1]="Monkey";

//I like Dog,Cat and Tiger.I hate Monkey
echo "I like ".$animal[0].",".$animal[1]." and ".$animal[2].".I hate ".$animal2[1];
echo "<br>";
//获取长度
echo count($animal); //3

echo "<br>";
//遍历数组
for($i=0;$i<count($animal);$i++){
    echo $animal[$i];
    echo "<br>";
}

2. 关联数组 : 带有指定键的数组

键 => 值

//关联数组
$student=array("DogFly"=>"10","未成年"=>"15","网购用"=>"21");

$goods['mushroom']="5";
$goods['eggplant']="6";
$goods['cucumber']="9";

//输出,这边都要用单引号
echo "DogFly is ".$student['DogFly']."<br>";
echo "未成年 is ".$student['未成年']."<br>";
echo "网购用 is {$student['网购用']}";

echo "<br>";
//遍历
foreach($goods as $i=>$i_value){
    echo "vegetable=".$i.",amount=".$i_value;
    echo "<br>";
}

3. 多维数组 : 包含一个或多个数组的数组

数组排序

• 索引数组

$a=array(65,45,78,12,32);
$animal=array("Dog","Cat","Tiger");

sort($a);
sort($animal);
for($i=0;$i<count($a);$i++){
    echo $a[$i]." ";    //升序
}
echo "<br>";
for($i=0;$i<count($animal);$i++){
    echo "$animal[$i]"." "; //按字母排
}
echo "<br>";
rsort($a);  //降序
for($i=0;$i<count($a);$i++){
    echo $a[$i]." ";
}

• 关联数组

$student=array("DogFly"=>"16","未成年"=>"15","网购用"=>"21");

asort($student);

foreach($student as $key=>&$value){
    //根据value的值升序排
    echo $key." : ".$value;
    echo "<br>";
}

echo "<br>";
ksort($student);    //根据key的值排序

foreach($student as $key=>&$value){
    echo $key." : ".$value;
    echo "<br>";
}

arsort($student);   //根据value降序排

krsort($student);   //根据key降序排