This article mainly introduces the basic array of PHP, which has certain reference value. Now I share it with everyone. Friends in need can refer to it
$arr = array("a","b","c"); $arr1 = array("a"=>1,"b"=>2,5,10=>100); //关联数组 $arr2 = array(); $arr2[] = "15"; $arr2[] = 15; $arr3[] =100; $arr3[] =10; $arr3[] ='中国梦'; echo $arr3[0];
<br/>
If there are duplicate subscripts, the latter one will overwrite the previous one.
The order of the array units is determined by the order in which they are put in, not the subscripts
Division by key-value relationship
Index array associative array mixed array
Divided by the dimensions of the array
One-dimensional array multi-dimensional array
// 求一个一维数组的平均值 $a = array(1,11,12,13,100); $n =count($a); $sum =0; for ($i=0; $i <$n ; $i++) { $sum+=$a[$i]; } echo "一维数组的平均值是".$sum/$n."<br/>"; // 求一个二维数组的平均值 $a1 = array( array(10,11,100), array(10,101,100), array(100,300,100,400), ); $len = count($a1); $sum = 0; $c = 0; for ($i=0; $i < $len; $i++) { $tempconut = count($a1[$i]); for ($k=0; $k < $tempconut; $k++) { $sum += $a1[$i][$k]; $c++; } } echo "二维数组的平均值为".$sum/$c."<br/>"; // 求一个一维数组的最大值 $a3 = array(10,100,1,300); $count = count($a3); $max = $a3[0] ; for ($i=0; $i < $count ; $i++) { if($max < $a3[$i]){ $max = $a3[$i]; } } echo "一维数组的最大值是".$max."<br>"; // 求一个二维数组的最大值 $a4 = array( array(100,0,10,999), array(100000000000000,100,10,9999), array(10,55,10000,999999999), ); $max = $a4[0][0]; for ($i=0; $i < count($a4); $i++) { for ($k=0; $k < count($a4[$i]) ; $k++) { if($max < $a4[$i][$k]){ $max = $a4[$i][$k]; } } } echo "二维数组的最大值是".$max."<br/>"; //交换一维数组的最大值和最小值 $arr5 = array(100,1,999,1024,888); $max_index = -1; $min_index = -1; $max = $arr5[0]; $min = $arr5[0]; for ($i=0; $i < count($arr5); $i++) { if($max < $arr5[$i]){ $max_index = $i;//最大值 $max = $arr5[$i]; } if($min > $arr5[$i]){ $min_index = $i;//最小值 $min = $arr5[$i]; } } $temp = $arr5[$max_index]; $arr5[$max_index] = $arr5[$min_index]; $arr5[$min_index] = $temp; echo "最大值索引是".$max_index."最小值索引是".$min_index."<br/>"; echo "一维数组最大值和最小值交换后的结果为".implode(" ",$arr5)."<br>";
<br/>
Traversal of arrays<br/>
$arr = array(1,100,35); foreach ($arr as $key => $value) { echo $value; }
//数组指针操作 $arr = array(10,200,500); do{ echo current($arr)."<br>"; }while(next($arr)); //指针默认在第一个元素处
$arr2 = array(100,88,1989,10,30); foreach ($arr2 as $key => $value) { } $key = key($arr2); $value = current($arr2); //遍历之后指针的位置 var_dump($key); //NULL var_dump($value); //false
for next traverse the array
$arr3 = array(1=>100,"aa"=>900,"中国梦"); for ($i=0; $i Copy after login
while each() list() traverse the array
Related recommendations:
The above is the detailed content of PHP basic array. For more information, please follow other related articles on the PHP Chinese website!