count_chars string function returns an array or string based on chars used its frequency and uniqueness

Count byte values used in a string

count_chars() counts byte values, not Unicode characters. With mode 1 it returns only byte values that occur at least once; use chr() to display each byte as a character when appropriate.

$counts = count_chars('banana', 1);foreach ($counts as $byte => $count) {
    echo chr($byte) . ': ' . $count . PHP_EOL;}

$str = "Welcome to plus2net PHP section";$position = count_chars($str,3);print_r($position);

Output

2HPWceilmnopstu

Using count_chars() function we can get many information about an input string. Here is the syntax

count_chars(string $string, int $mode = 0): array|string

$string : Main string to count chars
$mode : to get different return value. Default value is 0

$mode values

0: an array of all 256 byte values and their frequencies (including zero counts)
1: an array containing only byte values present in the string
2: an array containing only byte values absent from the string
3: a string containing the distinct byte values present, sorted in byte order
4: a string containing the distinct byte values absent, sorted in byte order

$str = "Welcome to plus2net PHP section";$position = count_chars($str,2);print_r($position);

Mode 2 returns an array containing only byte values absent from the string. By using print_r function we have displayed all keys with values of the array. Only absent byte values appear as keys, each with a zero count. Mode 0 includes all 256 byte values, both present and absent. With different mode values ( 0 to 4) we will get returns like this We will try some examples here

Setting Mode to 1

Mode 1 lists only byte values that occur in the string and their nonzero frequencies. Mode 0 includes zero-frequency byte values. Here is the code

$str = " Welcome to plus2net PHP section";$position = count_chars($str,1);print_r($position);

The output is here

Array ( [32] => 5 [50] => 1 [72] => 1 [80] => 2 [87] => 1 [99] => 2 [101] => 4 [105] => 1 [108] => 2
 [109] => 1 [110] => 2 [111] => 3 [112] => 1 [115] => 2 [116] => 3 [117] => 1 )

Let us change the mode value to 3, this is the only line to be changed.

$position = count_chars($str,3);

The output is here

2HPWceilmnopstu

So you can see the above chars only we have used in our main string.
Interesting applications can be developed by using this function like checking the string for frequency of used chars. You can also count punctuation such as the @ byte (64). This counts @ symbols only; it is not a valid way to count or verify email addresses.

Here is one example

$str = " ron@domain.com, kris@example.com, benoy@testing.com";$position = count_chars($str,1);echo $position[64]; // output is 3

String Functions str_word_count() Sub string count

Subhendu Mohapatra

Author & Instructor at plus2net

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count_chars() : returns information about the frequency of each character in a string

Count byte values used in a string

$mode values

Setting Mode to 1

Subhendu Mohapatra