PHP1234|PHP修炼之路|跟着明礼馨德一起修炼PHP

【函数功能】

该函数统计指定字符串中所用字符的信息。

【函数语法】

count_chars ($string, $mode = null)

【参数说明】

$string：必需，要检查的字符串。
$mode：可选，返回模式。默认是 0。以下是不同的返回模式：
0 - 数组，ASCII 值为键名，出现的次数为键值
1 - 数组，ASCII 值为键名，出现的次数为键值，只列出出现次数大于 0 的值
2 - 数组，ASCII 值为键名，出现的次数为键值，只列出出现次数等于 0 的值
3 - 字符串，带有所有使用过的不同的字符
4 - 字符串，带有所有未使用过的不同的字符

【演示程序】

<?php
        /**
         * count_chars ($string, $mode = null)
         * **/
        $string = "hello i am PHP!";
        var_dump(count_chars($string)) ;//$mode默认是0
        echo "<br>";
        var_dump(count_chars($string,1));
        echo "<br>";
        var_dump(count_chars($string,2));
        echo "<br>";
        var_dump(count_chars($string,3));
        echo "<br>";
        var_dump(count_chars($string,4));
?>

【输出结果】

array(256) { [0]=> int(0) [1]=> int(0) [2]=> int(0) [3]=> int(0) [4]=> int(0) [5]=> int(0) [6]=> int(0) [7]=> int(0) [8]=> int(0) [9]=> int(0) [10]=> int(0) [11]=> int(0) [12]=> int(0) [13]=> int(0) [14]=> int(0) [15]=> int(0) [16]=> int(0) [17]=> int(0) [18]=> int(0) [19]=> int(0) [20]=> int(0) [21]=> int(0) [22]=> int(0) [23]=> int(0) [24]=> int(0) [25]=> int(0) [26]=> int(0) [27]=> int(0) [28]=> int(0) [29]=> int(0) [30]=> int(0) [31]=> int(0) [32]=> int(3) [33]=> int(1) [34]=> int(0) [35]=> int(0) [36]=> int(0) [37]=> int(0) [38]=> int(0) [39]=> int(0) [40]=> int(0) [41]=> int(0) [42]=> int(0) [43]=> int(0) [44]=> int(0) [45]=> int(0) [46]=> int(0) [47]=> int(0) [48]=> int(0) [49]=> int(0) [50]=> int(0) [51]=> int(0) [52]=> int(0) [53]=> int(0) [54]=> int(0) [55]=> int(0) [56]=> int(0) [57]=> int(0) [58]=> int(0) [59]=> int(0) [60]=> int(0) [61]=> int(0) [62]=> int(0) [63]=> int(0) [64]=> int(0) [65]=> int(0) [66]=> int(0) [67]=> int(0) [68]=> int(0) [69]=> int(0) [70]=> int(0) [71]=> int(0) [72]=> int(1) [73]=> int(0) [74]=> int(0) [75]=> int(0) [76]=> int(0) [77]=> int(0) [78]=> int(0) [79]=> int(0) [80]=> int(2) [81]=> int(0) [82]=> int(0) [83]=> int(0) [84]=> int(0) [85]=> int(0) [86]=> int(0) [87]=> int(0) [88]=> int(0) [89]=> int(0) [90]=> int(0) [91]=> int(0) [92]=> int(0) [93]=> int(0) [94]=> int(0) [95]=> int(0) [96]=> int(0) [97]=> int(1) [98]=> int(0) [99]=> int(0) [100]=> int(0) [101]=> int(1) [102]=> int(0) [103]=> int(0) [104]=> int(1) [105]=> int(1) [106]=> int(0) [107]=> int(0) [108]=> int(2) [109]=> int(1) [110]=> int(0) [111]=> int(1) [112]=> int(0) [113]=> int(0) [114]=> int(0) [115]=> int(0) [116]=> int(0) [117]=> int(0) [118]=> int(0) [119]=> int(0) [120]=> int(0) [121]=> int(0) [122]=> int(0) [123]=> int(0) [124]=> int(0) [125]=> int(0) [126]=> int(0) [127]=> int(0) [128]=> int(0) [129]=> int(0) [130]=> int(0) [131]=> int(0) [132]=> int(0) [133]=> int(0) [134]=> int(0) [135]=> int(0) [136]=> int(0) [137]=> int(0) [138]=> int(0) [139]=> int(0) [140]=> int(0) [141]=> int(0) [142]=> int(0) [143]=> int(0) [144]=> int(0) [145]=> int(0) [146]=> int(0) [147]=> int(0) [148]=> int(0) [149]=> int(0) [150]=> int(0) [151]=> int(0) [152]=> int(0) [153]=> int(0) [154]=> int(0) [155]=> int(0) [156]=> int(0) [157]=> int(0) [158]=> int(0) [159]=> int(0) [160]=> int(0) [161]=> int(0) [162]=> int(0) [163]=> int(0) [164]=> int(0) [165]=> int(0) [166]=> int(0) [167]=> int(0) [168]=> int(0) [169]=> int(0) [170]=> int(0) [171]=> int(0) [172]=> int(0) [173]=> int(0) [174]=> int(0) [175]=> int(0) [176]=> int(0) [177]=> int(0) [178]=> int(0) [179]=> int(0) [180]=> int(0) [181]=> int(0) [182]=> int(0) [183]=> int(0) [184]=> int(0) [185]=> int(0) [186]=> int(0) [187]=> int(0) [188]=> int(0) [189]=> int(0) [190]=> int(0) [191]=> int(0) [192]=> int(0) [193]=> int(0) [194]=> int(0) [195]=> int(0) [196]=> int(0) [197]=> int(0) [198]=> int(0) [199]=> int(0) [200]=> int(0) [201]=> int(0) [202]=> int(0) [203]=> int(0) [204]=> int(0) [205]=> int(0) [206]=> int(0) [207]=> int(0) [208]=> int(0) [209]=> int(0) [210]=> int(0) [211]=> int(0) [212]=> int(0) [213]=> int(0) [214]=> int(0) [215]=> int(0) [216]=> int(0) [217]=> int(0) [218]=> int(0) [219]=> int(0) [220]=> int(0) [221]=> int(0) [222]=> int(0) [223]=> int(0) [224]=> int(0) [225]=> int(0) [226]=> int(0) [227]=> int(0) [228]=> int(0) [229]=> int(0) [230]=> int(0) [231]=> int(0) [232]=> int(0) [233]=> int(0) [234]=> int(0) [235]=> int(0) [236]=> int(0) [237]=> int(0) [238]=> int(0) [239]=> int(0) [240]=> int(0) [241]=> int(0) [242]=> int(0) [243]=> int(0) [244]=> int(0) [245]=> int(0) [246]=> int(0) [247]=> int(0) [248]=> int(0) [249]=> int(0) [250]=> int(0) [251]=> int(0) [252]=> int(0) [253]=> int(0) [254]=> int(0) [255]=> int(0) } 
array(11) { [32]=> int(3) [33]=> int(1) [72]=> int(1) [80]=> int(2) [97]=> int(1) [101]=> int(1) [104]=> int(1) [105]=> int(1) [108]=> int(2) [109]=> int(1) [111]=> int(1) } 
array(245) { [0]=> int(0) [1]=> int(0) [2]=> int(0) [3]=> int(0) [4]=> int(0) [5]=> int(0) [6]=> int(0) [7]=> int(0) [8]=> int(0) [9]=> int(0) [10]=> int(0) [11]=> int(0) [12]=> int(0) [13]=> int(0) [14]=> int(0) [15]=> int(0) [16]=> int(0) [17]=> int(0) [18]=> int(0) [19]=> int(0) [20]=> int(0) [21]=> int(0) [22]=> int(0) [23]=> int(0) [24]=> int(0) [25]=> int(0) [26]=> int(0) [27]=> int(0) [28]=> int(0) [29]=> int(0) [30]=> int(0) [31]=> int(0) [34]=> int(0) [35]=> int(0) [36]=> int(0) [37]=> int(0) [38]=> int(0) [39]=> int(0) [40]=> int(0) [41]=> int(0) [42]=> int(0) [43]=> int(0) [44]=> int(0) [45]=> int(0) [46]=> int(0) [47]=> int(0) [48]=> int(0) [49]=> int(0) [50]=> int(0) [51]=> int(0) [52]=> int(0) [53]=> int(0) [54]=> int(0) [55]=> int(0) [56]=> int(0) [57]=> int(0) [58]=> int(0) [59]=> int(0) [60]=> int(0) [61]=> int(0) [62]=> int(0) [63]=> int(0) [64]=> int(0) [65]=> int(0) [66]=> int(0) [67]=> int(0) [68]=> int(0) [69]=> int(0) [70]=> int(0) [71]=> int(0) [73]=> int(0) [74]=> int(0) [75]=> int(0) [76]=> int(0) [77]=> int(0) [78]=> int(0) [79]=> int(0) [81]=> int(0) [82]=> int(0) [83]=> int(0) [84]=> int(0) [85]=> int(0) [86]=> int(0) [87]=> int(0) [88]=> int(0) [89]=> int(0) [90]=> int(0) [91]=> int(0) [92]=> int(0) [93]=> int(0) [94]=> int(0) [95]=> int(0) [96]=> int(0) [98]=> int(0) [99]=> int(0) [100]=> int(0) [102]=> int(0) [103]=> int(0) [106]=> int(0) [107]=> int(0) [110]=> int(0) [112]=> int(0) [113]=> int(0) [114]=> int(0) [115]=> int(0) [116]=> int(0) [117]=> int(0) [118]=> int(0) [119]=> int(0) [120]=> int(0) [121]=> int(0) [122]=> int(0) [123]=> int(0) [124]=> int(0) [125]=> int(0) [126]=> int(0) [127]=> int(0) [128]=> int(0) [129]=> int(0) [130]=> int(0) [131]=> int(0) [132]=> int(0) [133]=> int(0) [134]=> int(0) [135]=> int(0) [136]=> int(0) [137]=> int(0) [138]=> int(0) [139]=> int(0) [140]=> int(0) [141]=> int(0) [142]=> int(0) [143]=> int(0) [144]=> int(0) [145]=> int(0) [146]=> int(0) [147]=> int(0) [148]=> int(0) [149]=> int(0) [150]=> int(0) [151]=> int(0) [152]=> int(0) [153]=> int(0) [154]=> int(0) [155]=> int(0) [156]=> int(0) [157]=> int(0) [158]=> int(0) [159]=> int(0) [160]=> int(0) [161]=> int(0) [162]=> int(0) [163]=> int(0) [164]=> int(0) [165]=> int(0) [166]=> int(0) [167]=> int(0) [168]=> int(0) [169]=> int(0) [170]=> int(0) [171]=> int(0) [172]=> int(0) [173]=> int(0) [174]=> int(0) [175]=> int(0) [176]=> int(0) [177]=> int(0) [178]=> int(0) [179]=> int(0) [180]=> int(0) [181]=> int(0) [182]=> int(0) [183]=> int(0) [184]=> int(0) [185]=> int(0) [186]=> int(0) [187]=> int(0) [188]=> int(0) [189]=> int(0) [190]=> int(0) [191]=> int(0) [192]=> int(0) [193]=> int(0) [194]=> int(0) [195]=> int(0) [196]=> int(0) [197]=> int(0) [198]=> int(0) [199]=> int(0) [200]=> int(0) [201]=> int(0) [202]=> int(0) [203]=> int(0) [204]=> int(0) [205]=> int(0) [206]=> int(0) [207]=> int(0) [208]=> int(0) [209]=> int(0) [210]=> int(0) [211]=> int(0) [212]=> int(0) [213]=> int(0) [214]=> int(0) [215]=> int(0) [216]=> int(0) [217]=> int(0) [218]=> int(0) [219]=> int(0) [220]=> int(0) [221]=> int(0) [222]=> int(0) [223]=> int(0) [224]=> int(0) [225]=> int(0) [226]=> int(0) [227]=> int(0) [228]=> int(0) [229]=> int(0) [230]=> int(0) [231]=> int(0) [232]=> int(0) [233]=> int(0) [234]=> int(0) [235]=> int(0) [236]=> int(0) [237]=> int(0) [238]=> int(0) [239]=> int(0) [240]=> int(0) [241]=> int(0) [242]=> int(0) [243]=> int(0) [244]=> int(0) [245]=> int(0) [246]=> int(0) [247]=> int(0) [248]=> int(0) [249]=> int(0) [250]=> int(0) [251]=> int(0) [252]=> int(0) [253]=> int(0) [254]=> int(0) [255]=> int(0) } 
string(11) " !HPaehilmo" 
string(245) "
	 "#$%&'()*+,-./0123456789:;<=>?@ABCDEFGIJKLMNOQRSTUVWXYZ[\]^_`bcdfgjknpqrstuvwxyz{|}~€亗儎厗噲墛媽崕彁憭摂晼棙櫄洔潪煚、￥ウЖ┆???辈炒刀犯购患骄坷谅媚牌侨墒颂臀闲岩釉罩棕仝圮蒉哙徕沅彐玷殛腱眍镳耱篝貊鼬????"

【特别注意】

1.PHP 版本：4+。

【原版定义】

/**
 * Return information about characters used in a string
 * @link http://www.php.net/manual/en/function.count-chars.php
 * @param string string <p>
 * The examined string.
 * </p>
 * @param mode int[optional] <p>
 * See return values.
 * </p>
 * @return mixed Depending on mode
 * count_chars returns one of the following:
 * 0 - an array with the byte-value as key and the frequency of
 * every byte as value.
 * 1 - same as 0 but only byte-values with a frequency greater
 * than zero are listed.
 * 2 - same as 0 but only byte-values with a frequency equal to
 * zero are listed.
 * 3 - a string containing all unique characters is returned.
 * 4 - a string containing all not used characters is returned.
 */

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