Different Array Sorting Functions

We all are familiar with arrays. But PHP provides lot of array functions. Those functions help us to reduce code length and save time. Here I am trying to point out some of the useful array sorting functions.

sort

To sort an array

Syntax : sort($array,$flags)
sort functiom has four flags.They are :
SORT_REGULAR - compare items normally
SORT_NUMERIC - compare items numerically
SORT_STRING - compare items as strings
SORT_LOCALE_STRING - compare items as strings, based on the current locale

eg :

$arr = array( 35, 40, 20, 14, 36);
sort($arr);
foreach ($arr as $key => $val) {
echo "arr[" . $key . "] = " . $val . "\n";
}

You will get following Output

arr[0] = 14 arr[1] = 20 arr[2] = 35 arr[3] = 36 arr[4] = 40

rsort

rsort function sorts an array in reverse order. This function is just opposite of sort function.

eg :
$arr = array( 35, 40, 20, 14, 36);
rsort($arr);
foreach ($arr as $key => $val) {
echo "arr[" . $key . "] = " . $val . "\n";
}
You will get following Output
arr[0] = 40 arr[1] = 36 arr[2] = 35 arr[3] = 20 arr[4] = 14

asort

asort function is similar to sort function. The only difference is it will not change the array index.

eg :

$arr = array( 35, 40, 20, 14, 36);
asort($arr);
foreach ($arr as $key => $val) {
echo "arr[" . $key . "] = " . $val . "\n";
}

You will get following Output

arr[3] = 14 arr[2] = 20 arr[0] = 35 arr[4] = 36 arr[1] = 40

arsort

arsort function is similar to rsort function. The only difference is it will not
change the array index.

eg :

$arr = array( 35, 40, 20, 14, 36);
arsort($arr);
foreach ($arr as $key => $val) {
echo "arr[" . $key . "] = " . $val . "\n";
}

You will get following Output

arr[1] = 40 arr[4] = 36 arr[0] = 35 arr[2] = 20 arr[3] = 14

ksort

ksort function will sort an array by key.

eg :

$arr = array( 35, 40, 20, 14, 36);
ksort($arr);
foreach ($arr as $key => $val) {
echo "arr[" . $key . "] = " . $val . "\n";
}

You will get following Output

arr[0] = 35 arr[1] = 40 arr[2] = 20 arr[3] = 14 arr[4] = 36

krsort

krsort function will sort an array by key in reverse order.

eg :

$arr = array( 35, 40, 20, 14, 36);
krsort($arr);
foreach ($arr as $key => $val) {
echo "arr[" . $key . "] = " . $val . "\n";
}

You will get following Output

arr[4] = 36 arr[3] = 14 arr[2] = 20 arr[1] = 40 arr[0] = 35