PHP Arrays
An array is a very special variable, which can hold more than one value at a time. It stores data items of similar types under a single identifier and hence simplify the data item management.
Array comes in use when we have to use multiple data items.
Suppose, we want to make a list of good cars manufacturer. So, generally how can one do:
$car1 = “Volvo”;
$car2 = “BMW”;
$car3 = “Toyoto”;
$car4 = “Ford”;
$car5 = “Tesla”;
But, with the help of an array we can store these all cars brand name in one variable.
$cars = ("Volvo", "BMW", "Toyoto", "Ford", "Tesla");
How to create an array:
Syntax- Array();
How to calculate the length of an array in php?
The count() function is used to calculate the length (number of elements) of an array.
In PHP, there are three types of array –
- Indexed array – array with numeric index
- Associative array – array with defined keys
- Multidimensional array – array containing one or more array
Indexed array
In indexed array, elements are represent by numeric number. By default, the index number starts from 0.
Indexed array can be created in two ways –
Let’s look below examples –
Elements are stored assuming first element at 0 index, second element at 1 index and so on.
$cars = array("BMW", "Toyoto", "Volvo");
Elements can be directly assign to the corresponding index numbers.
$cars[0] = "BMW"; $cars[1] = "Toyoto"; $cars[2] = "Volvo";
Loop through an Indexed array
We can print all elements/values of an array with the help of loop. Let’s understand this with an example-
Using for loop –
<?php
$cars = array("Volvo", "BMW", "Toyoto", "Ford", "Tesla");
$array_length = count($cars);
for($i=0; $i < $array_length; $i++)
{
echo $cars[$i];
echo "<br>";
}
?>
//Both will produce same output
Volvo
BMW
Toyota
Ford
Tesla
Using foreach –
<?php
$cars = array("Volvo", "BMW", "Toyoto", "Ford", "Tesla");
foreach($cars as $car)
{
echo $car;
echo "<br>";
}
?>
//Both will produce same output
Volvo
BMW
Toyota
Ford
Tesla
Associative array
In associative array, index or key are represented by a string. It is similar to indexed/numeric array. In indexed array, index is represented by numbers, whereas in this array string is used as indexing. This type of association is called key-value pair array.
You can create an associative array in two ways:
$cars = array(“Volvo” => “Black”, “BMW” => “White”, “Audi” => “Black”, “Ford” => “Red”);
Same array can be created as below :
$cars[“Volvo”] = “Black”;
$cars[“BMW”] = “White”;
$cars[“Audi”] = “Black”;
$cars[“Ford”] = “Red”;
Let’s understand with the help of example –
<?php
$cars = array("Volvo" => "black", "BMW" => "white", "Audi" => "black", "Ford" => "red");
echo "I have a BMW car of color " . $cars['BMW'] . "." ;
?>
//Output
I have a BMW car of color white
Loop through an Associative array
<?php
$cars = array("Volvo" => "black", "BMW" => "white", "Audi" => "black", "Ford" => "red");
foreach($cars as $key => $value)
{
echo "M.S.Dhoni has " . $value . " colored " . $key;
echo "<br>";
}
?>
//Output
M.S.Dhoni has black colored Volvo.
M.S.Dhoni has white colored BMW.
M.S.Dhoni has black colored Audi.
M.S.Dhoni has red colored Ford.
Multidimensional array
In multidimensional array, each element of the main array can also be an array. It is array in array.
Php supports two, three, four dimensional arrays etc. However it will become complex to manage higher dimensional arrays.
PHP – Two-dimensional arrays
A two dimensional array is an array of array for each element of main array. Let us understand with the below example of an employees details under a department of a company.
- Employee name
- Employee age
- Employee salary
- Employee department
- Employee address
Here, for each employee you have create an detail array under main array of employees:
<?php
$employees = array(
array('Melvin', 35, 35000, 'IT', 'Mumbai'),
array('Sumant', 26, 55000, 'Operation', 'Noida'),
array('Mayank', 40, 75000, 'Technology', 'Noida'),
array('Brijesh', 55, 95000, 'IT', 'Bhopal')
);
echo "<table>";
echo "<thead>";
echo "<tr>";
echo "<th>Name</th>";
echo "<th>Age</th>";
echo "<th>Salary</th>";
echo "<th>Department</th>";
echo "<th>City</th>";
echo "</tr>";
echo "</thead>";
echo "<tbody>";
echo "<tr>";
echo "<td>" . $employees[0][0] . "</td>";
echo "<td>" . $employees[0][1] . "</td>";
echo "<td>" . $employees[0][2] . "</td>";
echo "<td>" . $employees[0][3] . "</td>";
echo "<td>" . $employees[0][4] . "</td>";
echo "</tr>";
echo "<tr>";
echo "<td>" . $employees[1][0] . "</td>";
echo "<td>" . $employees[1][1] . "</td>";
echo "<td>" . $employees[1][2] . "</td>";
echo "<td>" . $employees[1][3] . "</td>";
echo "<td>" . $employees[1][4] . "</td>";
echo "</tr>";
echo "<tr>";
echo "<td>" . $employees[2][0] . "</td>";
echo "<td>" . $employees[2][1] . "</td>";
echo "<td>" . $employees[2][2] . "</td>";
echo "<td>" . $employees[2][3] . "</td>";
echo "<td>" . $employees[2][4] . "</td>";
echo "</tr>";
echo "<tr>";
echo "<td>" . $employees[3][0] . "</td>";
echo "<td>" . $employees[3][1] . "</td>";
echo "<td>" . $employees[3][2] . "</td>";
echo "<td>" . $employees[3][3] . "</td>";
echo "<td>" . $employees[3][4] . "</td>";
echo "</tr>";
?>
//Output
Name Age Salary Department City
Melvin 35 35000 IT Mumbai
Sumant 26 55000 Operation Noida
Melvin 40 75000 Technology Noida
Brijesh 55 95000 IT Bhopal
Loop through two dimensional array.
<?php
$employees = array(
array(
'name' => 'Melvin',
'age' => 35,
'salary' => 35000,
'dept' => 'IT',
'city' => 'Mumbai'
),
array(
'name' => 'Sumant',
'age' => 26,
'salary' => 55000,
'dept' => 'Operation',
'city' => 'Noida'
),
array(
'name' => 'Melvin',
'age' => 40,
'salary' => 75000,
'dept' => 'Technology',
'city' => 'Noida'
),
array(
'name' => 'Brijesh',
'age' => 55,
'salary' => 95000,
'dept' => 'IT',
'city' => 'Bhopal'
)
);
echo "<table>";
echo "<thead>";
echo "<tr>";
echo "<th>Name</th>";
echo "<th>Age</th>";
echo "<th>Salary</th>";
echo "<th>Department</th>";
echo "<th>City</th>";
echo "</tr>";
echo "</thead>";
echo "<tbody>";
foreach ($employees as $employee) {
echo "<tr>";
echo "<td>" . $employee['name'] . "</td>";
echo "<td>" . $employee['age'] . "</td>";
echo "<td>" . $employee['salary'] . "</td>";
echo "<td>" . $employee['dept'] . "</td>";
echo "<td>" . $employee['city'] . "</td>";
echo "</tr>";
}
echo "</tbody>";
echo "</table>";
?>
//Output
Name Age Salary Department City
Melvin 35 35000 IT Mumbai
Sumant 26 55000 Operation Noida
Melvin 40 75000 Technology Noida
Brijesh 55 95000 IT Bhopal
