How to print array with php

In PHP programming, it is often necessary to output the contents of an array for debugging or other purposes. Printing an array is one of the commonly used operations in PHP. PHP has a variety of methods for outputting arrays, and this article will introduce several of them.

1. print_r function

The print_r function is one of the most commonly used methods of printing arrays in PHP. It will print out the keys and values ​​of the array. The syntax of the print_r function is as follows:

print_r($array);

The sample code is as follows:

<?php
$array = array("name"=>"Tom", "age"=>20, "gender"=>"Male");
print_r($array);
?>

The print result is as follows:

Array
(
    [name] => Tom
    [age] => 20
    [gender] => Male
)

If you need to store the print result of the array into a variable, you can use The second parameter of the print_r function:

<?php
$array = array("name"=>"Tom", "age"=>20, "gender"=>"Male");
$output = print_r($array, true);
echo $output;
?>

2. var_dump function

The var_dump function is also one of the commonly used methods to print arrays in PHP. It can output the keys and values ​​of the array, as well as data type and length information. The syntax of the var_dump function is as follows:

var_dump($array);

The sample code is as follows:

<?php
$array = array("name"=>"Tom", "age"=>20, "gender"=>"Male");
var_dump($array);
?>

The print result is as follows:

array(3) {
  ["name"]=>
  string(3) "Tom"
  ["age"]=>
  int(20)
  ["gender"]=>
  string(4) "Male"
}

Similar to the print_r function, if you need to store the print result of the array into a In variables, you can use the second parameter of the var_dump function:

<?php
$array = array("name"=>"Tom", "age"=>20, "gender"=>"Male");
$output = var_dump($array, true);
echo $output;
?>

3. echo function

The echo function can also output an array, but it can only output the value of the array, not the value of the array. Output the keys of the array. The sample code is as follows:

<?php
$array = array("Tom", "20", "Male");
echo $array[0] . ", " . $array[1] . ", " . $array[2];
?>

The printing result is as follows:

Tom, 20, Male

4. foreach loop

The keys and values ​​in the array can also be output using the foreach loop. The sample code is as follows:

<?php
$array = array("name"=>"Tom", "age"=>20, "gender"=>"Male");
foreach ($array as $key => $value) {
    echo $key . ": " .$value . "<br>";
}
?>

The printing result is as follows:

name: Tom
age: 20
gender: Male

The above are several methods for printing arrays in PHP. Developers can choose to use one or more of them according to the specific situation. Implement output and debugging of arrays.

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