count_chars
(PHP 4, PHP 5)
count_chars -- 返回字符串所用字符的信息
说明
mixed
count_chars ( string string [, int mode] )
统计 string
中每个字节值(0..255)出现的次数,使用多种模式返回结果。可选参数
mode
默认值为
0。根据不同的
mode
,count_chars()
返回下列不同的结果:
0 - 以所有的每个字节值作为键名,出现次数作为值的数组。
1 - 与 0 相同,但只列出出现次数大于零的字节值。
2 - 与 0 相同,但只列出出现次数等于零的字节值。
3 - 返回由所有使用了的字节值组成的字符串。
4 - 返回由所有未使用的字节值组成的字符串。
例 1. count_chars() 示例
<?php $data = "Two Ts and one F.";
foreach (count_chars($data, 1) as $i => $val) { echo "There were $val instance(s) of \"" , chr($i) , "\" in the string.\n"; } ?>
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上例将输出: There were 4 instance(s) of " " in the string.
There were 1 instance(s) of "." in the string.
There were 1 instance(s) of "F" in the string.
There were 2 instance(s) of "T" in the string.
There were 1 instance(s) of "a" in the string.
There were 1 instance(s) of "d" in the string.
There were 1 instance(s) of "e" in the string.
There were 2 instance(s) of "n" in the string.
There were 2 instance(s) of "o" in the string.
There were 1 instance(s) of "s" in the string.
There were 1 instance(s) of "w" in the string. |
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参见 strpos() 和
substr_count()。