How to get specified column value from php array

Arrays are a very important data type in PHP and are an integral part of most programming languages. Arrays can contain one or more values, and each value can be accessed by index or key.

In PHP, the value of an array can be any type of data, including strings, numbers, Boolean values, objects and even other arrays. There are several different ways to access values ​​in an array, one of which is to take the value of a specified column.

The following are the basic steps on how to get the value of a specified column:

1. Define a multidimensional array

Multidimensional array is a very powerful method in PHP Data structure, which can contain other arrays. In this example, we will use a two-dimensional array with multiple rows and columns.

The following is an example of an array containing three rows and three columns:

$array = array(
  array('name' => 'John', 'age' => 20, 'country' => 'USA'),
  array('name' => 'Mary', 'age' => 25, 'country' => 'Canada'),
  array('name' => 'Peter', 'age' => 30, 'country' => 'UK')
);

This array has three rows and three columns, each row contains three key-value pairs, They are name, age and country respectively.

2. Define an array containing specified columns

In order to get the value of a specific column, we need to define a new array that only contains the columns we need. In PHP, we can easily extract a specific column from an array using the array_column function.

The following is a code example to extract the name column:

$names = array_column($array, 'name');

Among them, the first parameter of the array_column function is the array of columns to be extracted, The second parameter is the column name to be extracted.

Now, the $names variable contains the value of the name column in the $array array. In this case, it should contain the three string values ​​John, Mary, and Peter.

3. Output the results

The last step is to output the results on the screen. For this we can use PHP’s print_r function.

The following is a complete code example:

$array = array(
  array('name' => 'John', 'age' => 20, 'country' => 'USA'),
  array('name' => 'Mary', 'age' => 25, 'country' => 'Canada'),
  array('name' => 'Peter', 'age' => 30, 'country' => 'UK')
);

$names = array_column($array, 'name');

print_r($names);

The output result should be:

Array
(
    [0] => John
    [1] => Mary
    [2] => Peter
)

This shows that we successfully obtained from the $array array The value of the name column is retrieved and stored in the $names variable.

Summary

In PHP, arrays are one of the most important and commonly used data types. We can use the array_column function to easily extract the value of a specific column, making our program more flexible and powerful.

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