Home Backend Development PHP Tutorial Example of using count to get the length of a multidimensional array in PHP

Example of using count to get the length of a multidimensional array in PHP

May 26, 2018 pm 03:16 PM
count javascript php

In the previous article, we introduced to you how to obtain the length of php array, but the array is divided into one-dimensional array, multidimensional array, then This article describes how to implement count to obtain the length of a multidimensional array in PHP. Share it with everyone for your reference. The specific analysis is as follows:

Let’s first take a look at the results of the following program:

$numb=array(             
array(10,15,30),array(10,15,30),array(10,15,30) 
);  
echo count($numb,1);
Copy after login

A.3
B.12
C.6
D.9
The answer is that if mode is set to COUNT_RECURSIVE (or 1) in the B
count function, the number of elements in the array in the multi-dimensional array will be recursively calculated (that is, 12 in your result). If mode is not set, it defaults to 0. Multidimensional arrays (arrays within arrays) are not detected (result 3).

The first thing to traverse is the outer arrayIt turns out that there are two elements ("color1", "color2", "color3") and then traverse ("color1" for 3
, "color2", "color3") The array results in 9 elements as 9
The result is 3+9=12

Reference example:

The code is as follows:

<?php
$fruits = array (
    array (1, 2,null,null, 5, 6),
    array (1, 2,null,null, 5, 6),
);
echo(count($fruits[0]));
?>
Copy after login

If you use an array defined in other ways, such as:
Copy the code as follows:

<?php
$fruits[0][0]=1;
$fruits[0][3]=1;
$fruits[0][4]=1;
echo(count($fruits[0]));
?>
Copy after login

In this way, 3 will be output, because arrays in PHP do not require indexing Continuous, the reference manual has the following paragraph:
Array:
PHP The array in is actually an ordered graph. A graph is a mapping of values ​​to keys type. This type is optimized in many ways, so you can use it as a real array, or a list (vector), a hash table (an implementation of a graph), a dictionary, a set, a stack, a queue, and more possibilities sex. It's also easy to simulate a tree since you can use another PHP array as a value.
Example:
Get the length of the first dimension of a two-dimensional or multi-dimensional array. This is a common program judgment. For example, the array you read is a two-dimensional array:

<?php
$arr=array(
 0=>array(&#39;title&#39; => &#39;新闻1&#39;, &#39;viewnum&#39; => 123, &#39;content&#39; => &#39;ZAQXSWedcrfv&#39;),
 1=>array(&#39;title&#39; => &#39;新闻2&#39;, &#39;viewnum&#39; => 99, &#39;content&#39; => &#39;QWERTYUIOPZXCVBNM&#39;)
);
?>
Copy after login

If you want to count the length of the array $arr, that is to say, the two-dimensional array has only two news, the number you want is also 2, but if you use count($arr) different versions of php, statistics The results are different;
Later I found in the php manual that the count function has a second parameter, which is explained as follows:
The count function has two parameters:
0( or COUNT_NORMAL) is the default and does not detect multi-dimensional arrays (arrays within arrays);
1 (or COUNT_RECURSIVE) is for detecting multi-dimensional arrays,
So if you want to determine whether the read array $arr has news information, just To write like this:

<?php
if(is_array($arr) && count($arr,COUNT_NORMAL)>0 )
{
  .....
} else {
  .....
}
?>
Copy after login

You can use code like this to test the function:

<?php
$arr=array(
 0=>array(&#39;title&#39; => &#39;新闻1&#39;, &#39;viewnum&#39; => 123, &#39;content&#39; => &#39;ZAQXSWedcrfv&#39;),
 1=>array(&#39;title&#39; => &#39;新闻2&#39;, &#39;viewnum&#39; => 99, &#39;content&#39; => &#39;QWERTYUIOPZXCVBNM&#39;)
);
echo &#39;不统计多维数组:&#39;.count($arr,0);//count($arr,COUNT_NORMAL)
echo "<br/>";
echo &#39;统计多维数组:&#39;.count($arr,1);//count($arr,COUNT_RECURSIVE)
?>
Copy after login

Summary:

This article has solved the problem of obtaining the first dimension length of a two-dimensional or multi-dimensional array in PHP. Is it very simple to obtain the length of a PHP array? I hope it will be helpful to you!

Related recommendations:

How to get the length of php array


Method to determine php array dimension (php array length)


php array, php array length_PHP tutorial

The above is the detailed content of Example of using count to get the length of a multidimensional array in PHP. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

CakePHP Project Configuration CakePHP Project Configuration Sep 10, 2024 pm 05:25 PM

In this chapter, we will understand the Environment Variables, General Configuration, Database Configuration and Email Configuration in CakePHP.

PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian Dec 24, 2024 pm 04:42 PM

PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

CakePHP Date and Time CakePHP Date and Time Sep 10, 2024 pm 05:27 PM

To work with date and time in cakephp4, we are going to make use of the available FrozenTime class.

CakePHP File upload CakePHP File upload Sep 10, 2024 pm 05:27 PM

To work on file upload we are going to use the form helper. Here, is an example for file upload.

CakePHP Routing CakePHP Routing Sep 10, 2024 pm 05:25 PM

In this chapter, we are going to learn the following topics related to routing ?

Discuss CakePHP Discuss CakePHP Sep 10, 2024 pm 05:28 PM

CakePHP is an open-source framework for PHP. It is intended to make developing, deploying and maintaining applications much easier. CakePHP is based on a MVC-like architecture that is both powerful and easy to grasp. Models, Views, and Controllers gu

How To Set Up Visual Studio Code (VS Code) for PHP Development How To Set Up Visual Studio Code (VS Code) for PHP Development Dec 20, 2024 am 11:31 AM

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

CakePHP Creating Validators CakePHP Creating Validators Sep 10, 2024 pm 05:26 PM

Validator can be created by adding the following two lines in the controller.

See all articles