描述
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。
例子 1. count_chars() 示例
<?php
$data = "Two Ts and one F.";
$result = count_chars($data, 0);
for ($i=0; $i < count($result); $i++) {
if ($result[$i] != 0)
echo "There were $result[$i] instance(s) of \"" , chr($i) , "\" in the string.\n";
}
?>
|
下边为示例输出：
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. |
|
参见 strpos() 和
substr_count()。
