Php array length for

Get the length of an array in PHP.

This is a beginner’s guide on how to get the length of a PHP array. To count all of the elements in a PHP array, you can either use the count function or the sizeof function.

Counting the number of elements in a PHP array.

Do NOT use a loop to count the number of elements in array, as this would be extremely wasteful.

To count the number of elements in an array, you can use PHP’s native count function like so:

//An array of names. $names = array( 'John', 'Jason', 'Martina', 'Lisa', 'Tony' ); //Get the number of elements in the array by //using PHP's inbuilt count() function. $numElements = count($names); //Print it out. echo $numElements;

If you run the code snippet above, you will find that the output of count() is “5”. This is because there is five elements in the $names array.

Counting elements in a multidimensional array.

In some cases, you might need to count all of the elements in a multidimensional PHP array. To do this, you will need to use the count function’s second parameter, which is called mode.

To achieve this, we can simply pass the constant COUNT_RECURSIVE in as the second parameter:

//A multidimensional array. $arr = array( 1, 2, 10, array( 20, 21, 80 ) ); //Pass COUNT_RECURSIVE in as a second parameter. $numElements = count($arr, COUNT_RECURSIVE); //Print out the result echo $numElements;

Note that the code above will print out “7” instead of “6”. This is because the array containing 20, 21 and 80 is also considered to be an element (you’d be surprised by how many developers expect the length to be 6).

The difference between count and sizeof.

The count function and the sizeof function do the exact same thing. In fact, sizeof is merely an alias of the count function.

Personally, I would suggest that you stick to using the count function. This is because other programmers may expect the sizeof function to return the size of the array in bytes / memory.

Note that as of PHP 7.2, the count function will emit an E_WARNING error if you provide it with a variable that isn’t an array or a Countable object.

Источник

PHP Array Length: How to Find Array Length in PHP [With Examples]

Below is the example we can consider as key and value pair:

Note: we categorize Arrays as “indexed array” and “associative array” based on the key stipulation. The Indexed array has a default index that starts with ‘0’.The associative array includes the user-defined key index. We can use the keys for strings and natural numbers.

Check out our free courses to get an edge over the competition.

Explore Our Software Development Free Courses

upGrad’s Exclusive Software and Tech Webinar for you –

SAAS Business – What is So Different?

Check Out upGrad Java Bootcamp

How to create an Array in PHP?

$animals = array(“Bear”, “Leopard”, “Tiger”);

$animals = array(“Leopard”=>”Wild”, “Cow”=>”Domestic”, “Lion”=>”Wild”);

// loop through associative array and get key-value pairs

foreach($animals as $key => $value)

echo “Key=” . $key . “, Value=” . $value;

//two-dimensional array definition declaration

// two-dimensional array iteration declaration

Below is the image as a perfect example for the three-dimensional array:

Explore our Popular Software Engineering Courses

PHP | sizeof() Function

The sizeof() function is a built-in function in PHP, and we can use it to count the number of elements present in an array countable object.

Parameter: As per the above syntax example, this function accepts two parameters.

• array: This parameter defines the array which contains elements which we need to count.
• mode: This is an optional parameter, and here we specify the mode of the function. It can take two types of values as per the below:
  • 0: It is default, does not count all elements of multidimensional arrays
  • 1: It Counts the array recursively (It counts all the elements with multidimensional arrays)

  How to Check if a Value Exists in an Array in PHP

  Check if the value exists in an array in PHP

  Step 1 – Use the PHP in_array() function to test if a value exists in an array or not.

  Step 2 – Define the in_array() function

  As per the below code snippet Example:

  $zoo = array(“Leopard”, “Tiger”, “Elephant”, “Zebra”, “Rhino”, “Dear”);

  echo “The elephant was found in the zoo.”;

  echo “The tiger was found in the zoo.”;

  In-Demand Software Development Skills

  How to Count all Elements or Values in an Array in PHP

  We can use the PHP count() or sizeof() function to get the particular number of elements or values in an array.

  • The count() and sizeof() function returns 0 for a variable that we can initialize with an empty array.
  • If we do not set the value for a variable, it returns 0.

  Below is the code snippet:

  $days = array(“Sun”, “Mon”, “Tue”, “Wed”, “Thu”, “Fri”, “Sat”);

  How to Print or Echo all the Values of an Array in PHP

  • For printing the array values here we have different ways
  • The easiest method we have foreach loop

  As per the below example, we are repeating the $colors array and print all its elements using the echo or print statement.

  Below is the code snippet:

  $colors = array(“Yellow”, “Purple”, “Red”, “Brown”, “Skyblue”);

  // Loop through colors array

  How to Display Array Structure and Values in PHP

  Use the PHP print_r() or var_dump() Statement

  • For checking the structure and values of an array.
  • You can either use the PHP print_r() or var_dump() statement to see or check the structure and values of an array with an easily readable format on the screen.
  • The var_dump() statement provides better information than print_r().

  Below is the code snippet example we can consider for this:

  $cities = array(“Canada”, “Australia”, “New Jersey”);

  How to Remove the Last Element From an Array in PHP

  Use the PHP array_pop() function

  • For removing the particular value or element from the end of an array.
  • The array_pop() function returns the last value of an array.
  • If the array is empty (without element value in an array list), the returned value will be NULL.

  Below is the code snippet Example to explain how this function runs:

  $sports = array(“Tennis”, “Cricket”, “BasketBall”, “Badminton”);

  

  Learn Software Courses online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career.

  Read our Popular Articles related to Software Development

  Conclusion

  If you’re interested to learn more about PHP, full-stack software development, check out upGrad & IIIT-B’s Executive PG Program in Full-stack Software Development which is designed for working professionals and offers 500+ hours of rigorous training, 9+ projects, and assignments, IIIT-B Alumni status, practical hands-on capstone projects & job assistance with top firms.

  Rohan Vats

  Software Engineering Manager @ upGrad. Passionate about building large scale web apps with delightful experiences. In pursuit of transforming engineers into leaders.

  Our Trending Software Engineering Courses

  Our Popular Software Engineering Courses

  

  Popular Software Development Skills

  • React Courses
  • Javascript Courses
  • Core Java Courses
  • Data Structures Courses
  • ReactJS Courses
  • NodeJS Courses
  • Blockchain Courses
  • SQL Courses
  • Full Stack Development Courses
  • Big Data Courses
  • Devops Courses
  • NFT Courses
  • Cyber Security Courses
  • Cloud Computing Courses
  • Database Design Courses
  • Crypto Courses
  • Python Courses

  Frequently Asked Questions (FAQs)

  Arrays are useful data structures in PHP, which can be used to store multiple values under a single named variable, that too without any need of specifying the type of each individual value. Arrays are one of the fundamental data types in PHP. An array is a collection of elements which can be referenced by an index. You can add new elements, remove existing elements, or change the value stored in any element of an array.

  Finding the length of an array can be quite useful especially in cases where you want to loop through the array and fetch all or some elements inside it. If you want to find the length of an array in PHP, you can use the sizeof function and use the echo command along with it to print the length. The second method is using a function called: count(). This function differs in that it returns the number of elements in an array or object (not just their key values) and also counts the number of array levels in multidimensional arrays.

  PHP has a very rich set of core libraries. In PHP, we have an array of functions we can use to manipulate arrays in different ways without having to create a new function for specific cases. The most common array functions in PHP are: array_merge( $arrays ) — Combines two or more arrays, array_diff( $array1 , $array2 ) — Finds the difference between two arrays, array_map( $callback , $array ) — Creates an array by calling a user-defined function on every array element, array_filter( $array ) — Filters out all elements in an array that do not return true when passed to the callback function.

  Источник

  Array Length PHP Calculate PHP Array Length

  How to calculate the PHP array length? If you want to count the total number of elements or values in an array, you can easily do it by using PHP inbuilt functions called count() or sizeof(). You can find a detailed explanation with the example below that how you can calculate PHP array length.

  count(): PHP Array Length For Loop

  count(var array_or_countable, mode)

  If you don’t know what is an array then please see the detailed explanation of how arrays are created and used in PHP.

  array_or_countable

  The first argument is an array variable that is required to calculate the PHP array length. If the first argument is empty, an empty array or not set, then count() function will return 0. And, If the variable is specified but its data type is not an array, then, count() function will return 1. To avoid this, you can use the PHP inbuilt function isset() and check whether an array variable is set or not.

  mode

  The second argument is optional and can take two values either COUNT_NORMAL or COUNT_RECURSIVE. You can pass the value 0 and 1 instead of COUNT_NORMAL and COUNT_RECURSIVE that will make the same effect. The default value of the second argument is COUNT_NORMAL if no value passed as the second argument. Example #1 count() example

  $food = array('fruits' => array('orange', 'banana', 'apple'), 'veggie' => array('carrot', 'collard', 'pea')); // recursive count echo count($food, COUNT_RECURSIVE); // output 8 // normal count echo count($food); or count($food, COUNT_NORMAL ); // output 2

  In the above code block, We have created a multidimensional array. When we use count function in the RECURSIVE mode as a second argument, Output is 8. And, when we use count function in the NORMAL mode as a second argument or default mode, Output is 2.

  sizeof()— PHP Array Length?

  sizeof() is an alias of PHP count() function and accepts the same arguments as count(). If We replace the count() with sizeof() in the above example, the results of both functions will be the same for both functions calls. Many programmers who come from C language background expect sizeof() to return the amount of memory allocated. But, sizeof() — as described above — is an alias for count() in PHP. It is advised to always use count() instead of sizeof(). Because there is no guarantee for the alias function if they will exist or not in a future upgrade. So, you should always consider to maintain code standard as well as avoid to break the application due to the upgraded version.

  Источник