PHP count_​chars() Function

What is PHP count_​chars() Function?

If you want to do the following character analysis of a string, use count_chars() function.

  • List of characters that are used.
  • List of characters that aren’t used.
  • Number of times each character exists.

How PHP count_​chars() Function works?

The function takes every character from the string (which is the 1st parameter) and checks it with 256 ASCII values. What the function returns depends on the mode which is the 2nd parameter of the function. For modes and return values, see the parameter section below-

Syntax:

count_chars(string,mode)

Parameters:

The Function has 1 required parameter and 1 optional parameter-

string (Required): It specifies the string which is to be to analyzed.

mode (Optional): It specifies the operation needed to be performed on the string. There are 5 different types of modes – 0, 1, 2, 3, 4, 5

Return Values:

Below table describes the modes and their outcome which is the return value of the function-

Mode 0
(default)		The function returns an array of 256 elements. Each key is the value of 256 characters and its value is number of times each character appears in the string. Check example 1.
Mode 1The function returns an array and the number of element depends different number of characters in the string. Each key is the ASCII value of that character and its value is number of times the character appears in the string. Check example 2.
Mode 2The function returns an array and the number of element depends on the number of characters doesn’t appeared in the string. Each key is the ASCII value of that character and its value is number of times the character appears in the string. Check example 3.
Mode 3The function returns a string that contains all the unique characters of the string. Check example 4.
Mode 4The function returns a string that contains all the characters that doesn’t used in the 256 ASCII values. Check example 5.

Examples:

Example 1:

<?php
$str = "ABCC";
print_r(count_chars($str));
?>

Output:

Array ( [0] => 0 [1] => 0 [2] => 0 [3] => 0 [4] => 0 [5] => 0 [6] => 0 [7] => 0 [8] => 0 [9] => 0 [10] => 0 [11] => 0 [12] => 0 [13] => 0 [14] => 0 [15] => 0 [16] => 0 [17] => 0 [18] => 0 [19] => 0 [20] => 0 [21] => 0 [22] => 0 [23] => 0 [24] => 0 [25] => 0 [26] => 0 [27] => 0 [28] => 0 [29] => 0 [30] => 0 [31] => 0 [32] => 0 [33] => 0 [34] => 0 [35] => 0 [36] => 0 [37] => 0 [38] => 0 [39] => 0 [40] => 0 [41] => 0 [42] => 0 [43] => 0 [44] => 0 [45] => 0 [46] => 0 [47] => 0 [48] => 0 [49] => 0 [50] => 0 [51] => 0 [52] => 0 [53] => 0 [54] => 0 [55] => 0 [56] => 0 [57] => 0 [58] => 0 [59] => 0 [60] => 0 [61] => 0 [62] => 0 [63] => 0 [64] => 0 [65] => 1 [66] => 1 [67] => 2 [68] => 0 [69] => 0 [70] => 0 [71] => 0 [72] => 0 [73] => 0 [74] => 0 [75] => 0 [76] => 0 [77] => 0 [78] => 0 [79] => 0 [80] => 0 [81] => 0 [82] => 0 [83] => 0 [84] => 0 [85] => 0 [86] => 0 [87] => 0 [88] => 0 [89] => 0 [90] => 0 [91] => 0 [92] => 0 [93] => 0 [94] => 0 [95] => 0 [96] => 0 [97] => 0 [98] => 0 [99] => 0 [100] => 0 [101] => 0 [102] => 0 [103] => 0 [104] => 0 [105] => 0 [106] => 0 [107] => 0 [108] => 0 [109] => 0 [110] => 0 [111] => 0 [112] => 0 [113] => 0 [114] => 0 [115] => 0 [116] => 0 [117] => 0 [118] => 0 [119] => 0 [120] => 0 [121] => 0 [122] => 0 [123] => 0 [124] => 0 [125] => 0 [126] => 0 [127] => 0 [128] => 0 [129] => 0 [130] => 0 [131] => 0 [132] => 0 [133] => 0 [134] => 0 [135] => 0 [136] => 0 [137] => 0 [138] => 0 [139] => 0 [140] => 0 [141] => 0 [142] => 0 [143] => 0 [144] => 0 [145] => 0 [146] => 0 [147] => 0 [148] => 0 [149] => 0 [150] => 0 [151] => 0 [152] => 0 [153] => 0 [154] => 0 [155] => 0 [156] => 0 [157] => 0 [158] => 0 [159] => 0 [160] => 0 [161] => 0 [162] => 0 [163] => 0 [164] => 0 [165] => 0 [166] => 0 [167] => 0 [168] => 0 [169] => 0 [170] => 0 [171] => 0 [172] => 0 [173] => 0 [174] => 0 [175] => 0 [176] => 0 [177] => 0 [178] => 0 [179] => 0 [180] => 0 [181] => 0 [182] => 0 [183] => 0 [184] => 0 [185] => 0 [186] => 0 [187] => 0 [188] => 0 [189] => 0 [190] => 0 [191] => 0 [192] => 0 [193] => 0 [194] => 0 [195] => 0 [196] => 0 [197] => 0 [198] => 0 [199] => 0 [200] => 0 [201] => 0 [202] => 0 [203] => 0 [204] => 0 [205] => 0 [206] => 0 [207] => 0 [208] => 0 [209] => 0 [210] => 0 [211] => 0 [212] => 0 [213] => 0 [214] => 0 [215] => 0 [216] => 0 [217] => 0 [218] => 0 [219] => 0 [220] => 0 [221] => 0 [222] => 0 [223] => 0 [224] => 0 [225] => 0 [226] => 0 [227] => 0 [228] => 0 [229] => 0 [230] => 0 [231] => 0 [232] => 0 [233] => 0 [234] => 0 [235] => 0 [236] => 0 [237] => 0 [238] => 0 [239] => 0 [240] => 0 [241] => 0 [242] => 0 [243] => 0 [244] => 0 [245] => 0 [246] => 0 [247] => 0 [248] => 0 [249] => 0 [250] => 0 [251] => 0 [252] => 0 [253] => 0 [254] => 0 [255] => 0 )

Example 2:

<?php
$str = "ABCC";
print_r(count_chars($str, 1));
?>

Output:

Array ( [65] => 1 [66] => 1 [67] => 2 )

Example 3:

<?php
$str = "ABCC";
print_r(count_chars($str, 2));
?>

Output:

Array ( [0] => 0 [1] => 0 [2] => 0 [3] => 0 [4] => 0 [5] => 0 [6] => 0 [7] => 0 [8] => 0 [9] => 0 [10] => 0 [11] => 0 [12] => 0 [13] => 0 [14] => 0 [15] => 0 [16] => 0 [17] => 0 [18] => 0 [19] => 0 [20] => 0 [21] => 0 [22] => 0 [23] => 0 [24] => 0 [25] => 0 [26] => 0 [27] => 0 [28] => 0 [29] => 0 [30] => 0 [31] => 0 [32] => 0 [33] => 0 [34] => 0 [35] => 0 [36] => 0 [37] => 0 [38] => 0 [39] => 0 [40] => 0 [41] => 0 [42] => 0 [43] => 0 [44] => 0 [45] => 0 [46] => 0 [47] => 0 [48] => 0 [49] => 0 [50] => 0 [51] => 0 [52] => 0 [53] => 0 [54] => 0 [55] => 0 [56] => 0 [57] => 0 [58] => 0 [59] => 0 [60] => 0 [61] => 0 [62] => 0 [63] => 0 [64] => 0 [68] => 0 [69] => 0 [70] => 0 [71] => 0 [72] => 0 [73] => 0 [74] => 0 [75] => 0 [76] => 0 [77] => 0 [78] => 0 [79] => 0 [80] => 0 [81] => 0 [82] => 0 [83] => 0 [84] => 0 [85] => 0 [86] => 0 [87] => 0 [88] => 0 [89] => 0 [90] => 0 [91] => 0 [92] => 0 [93] => 0 [94] => 0 [95] => 0 [96] => 0 [97] => 0 [98] => 0 [99] => 0 [100] => 0 [101] => 0 [102] => 0 [103] => 0 [104] => 0 [105] => 0 [106] => 0 [107] => 0 [108] => 0 [109] => 0 [110] => 0 [111] => 0 [112] => 0 [113] => 0 [114] => 0 [115] => 0 [116] => 0 [117] => 0 [118] => 0 [119] => 0 [120] => 0 [121] => 0 [122] => 0 [123] => 0 [124] => 0 [125] => 0 [126] => 0 [127] => 0 [128] => 0 [129] => 0 [130] => 0 [131] => 0 [132] => 0 [133] => 0 [134] => 0 [135] => 0 [136] => 0 [137] => 0 [138] => 0 [139] => 0 [140] => 0 [141] => 0 [142] => 0 [143] => 0 [144] => 0 [145] => 0 [146] => 0 [147] => 0 [148] => 0 [149] => 0 [150] => 0 [151] => 0 [152] => 0 [153] => 0 [154] => 0 [155] => 0 [156] => 0 [157] => 0 [158] => 0 [159] => 0 [160] => 0 [161] => 0 [162] => 0 [163] => 0 [164] => 0 [165] => 0 [166] => 0 [167] => 0 [168] => 0 [169] => 0 [170] => 0 [171] => 0 [172] => 0 [173] => 0 [174] => 0 [175] => 0 [176] => 0 [177] => 0 [178] => 0 [179] => 0 [180] => 0 [181] => 0 [182] => 0 [183] => 0 [184] => 0 [185] => 0 [186] => 0 [187] => 0 [188] => 0 [189] => 0 [190] => 0 [191] => 0 [192] => 0 [193] => 0 [194] => 0 [195] => 0 [196] => 0 [197] => 0 [198] => 0 [199] => 0 [200] => 0 [201] => 0 [202] => 0 [203] => 0 [204] => 0 [205] => 0 [206] => 0 [207] => 0 [208] => 0 [209] => 0 [210] => 0 [211] => 0 [212] => 0 [213] => 0 [214] => 0 [215] => 0 [216] => 0 [217] => 0 [218] => 0 [219] => 0 [220] => 0 [221] => 0 [222] => 0 [223] => 0 [224] => 0 [225] => 0 [226] => 0 [227] => 0 [228] => 0 [229] => 0 [230] => 0 [231] => 0 [232] => 0 [233] => 0 [234] => 0 [235] => 0 [236] => 0 [237] => 0 [238] => 0 [239] => 0 [240] => 0 [241] => 0 [242] => 0 [243] => 0 [244] => 0 [245] => 0 [246] => 0 [247] => 0 [248] => 0 [249] => 0 [250] => 0 [251] => 0 [252] => 0 [253] => 0 [254] => 0 [255] => 0 )

Example 4:

<?php
$str = "ABCC";
echo count_chars($str, 3);
?>

Output:

ABC

Example 5:

<?php
$str = "ABCC";
echo count_chars($str, 4);
?>

Output:

    ¬ !"#$%&'()*+,-./0123456789:;<=>?@DEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~��������������������������������������������������������������������������������������������������������������������������������

Notes on count_​chars() Function:

The function works on ASCII characters only. It doesn’t work on multi-byte characters. For those types of operations, use mb_* functions.

PHP Version Support:

PHP 4, PHP 5, PHP 7, PHP 8

Summary: PHP count_​chars() Function

count_chars() function is one of the built-in string functions. Use this function to analyze characters of a string.

Reference:

https://www.php.net/manual/en/function.count-chars.php