ARRAYS IN PHP

Array is a collection of heterogeneous elements. PHP is loosely typed language, hence in this way we can store any type of value in array. Array is a collection of elements, where each element is a combination of key and value. By default, first element key starts with key 0. Difference between a variable and array is variable can store single value whereas an array can store collection of values. By using print_r function we can print all elements of array.

Example –

<?php

$num=array(10,20,30);

print_r($num); // print all elements of array

echo $num[1]; // prints only one element with key 1

?>

Output –

Array

(

    [0] => 10

    [1] => 20

    [2] => 30

)

20

Example –

<?php

$num=array(5,100=>10,20,50=>30,'scott');

print_r($num);

?>

Output –

Array

(

    [0] => 5

    [100] => 10

    [101] => 20

    [50] => 30

    [102] => scott // because of the highest previous address

)

Example –

<?php

$num=array(10,20,0=>30); // overrides 10 with 30

print_r($num);

?>

Output –

Array

(

    [0] => 30

    [1] => 20

)

Example –

<?php

$arr=array();

$arr[0]=10;

$arr[1]=20;

$arr[2]=30;

print_r($arr);

?>

Output –

Array

(

    [0] => 10

    [1] => 20

    [2] => 30

)

Array elements are of two types –

1. Numeric elements – Elements with number key comes under numeric elements.

2. Associative elements – Elements with string key comes under associative array.

Example –

<?php

$arr=array();

$arr[0]=10;

$arr['hr']="Scott";

$arr['admin']="John";

print_r($arr);

?>

Output –

Array

(

    [0] => 10

    [hr] => Scott

    [admin] => John

)