How to output only array key values ​​in php

Two methods of outputting only key values: 1. Use the "$array variable name [subscript]" statement to access a key value of the specified subscript, and then use the echo or print statement to output the single array key value. Syntax "echo $array variable name[subscript];" or "print $array variable name[subscript];". 2. Use the foreach statement to loop through the array, and then use the echo or print statement to output multiple array key values. The syntax is "foreach($array variable name as $v){echo $v;}".

The operating environment of this tutorial: Windows 7 system, PHP version 8.1, DELL G3 computer

php only outputs arrays Two methods of key values

Method 1. Output a single array key value

• First use "$array variable Name[subscript]" statement accesses an element of the specified subscript

• and then uses the echo or print statement to output a single array key value

<?php
header("Content-type:text/html;charset=utf-8");
$arr = array(11,null,12,2,3,4,5); 
var_dump($arr);
echo $arr[0]."<br>";
print $arr[2]."<br>";
?>

Method 2: Output multiple array key values

• First use the foreach statement to loop through the array

• Use echo or print statements to output multiple array key values

<?php
header("Content-type:text/html;charset=utf-8");
$arr = array(11,0,12,2,3,4,5); 
var_dump($arr);
foreach($arr as $v){
	echo $v."<br>";
	//print $v."<br>";
}
?>

Recommended study: "PHP Video Tutorial》

The above is the detailed content of How to output only array key values ​​in php. For more information, please follow other related articles on the PHP Chinese website!