str_split

(PHP 5, PHP 7, PHP 8)

str_split — 将字符串转换为数组

说明

str_split(string $string, int $length = 1): array

将一个字符串转换为数组。

参数

string: 输入字符串。
length: 每一段的长度。

返回值

如果指定了可选的 length 参数，返回数组中的每个元素长度均为 length 的块，除了最后一个块，如果字符串不是均匀划分，则可能会更短。默认 length 是 1，这意味着每个块的大小是一个字节。

错误／异常

如果 length 小于 1，将会抛出 ValueError。

更新日志

版本	说明
8.2.0	如果 `string` 为空，现在返回空 array。之前返回的 array 包含单个空字符串。
8.0.0	如果 `length` 小于 `1`，现在会抛出 ValueError；之前会触发 `E_WARNING` 级别的错误且函数会返回 `false`。

示例

示例 #1 str_split() 使用示例

<?php

$str = "Hello Friend";

$arr1 = str_split($str);
$arr2 = str_split($str, 3);

print_r($arr1);
print_r($arr2);

?>

以上示例会输出：

Array
(
    [0] => H
    [1] => e
    [2] => l
    [3] => l
    [4] => o
    [5] =>
    [6] => F
    [7] => r
    [8] => i
    [9] => e
    [10] => n
    [11] => d
)

Array
(
    [0] => Hel
    [1] => lo
    [2] => Fri
    [3] => end
)

注释

注意:
在处理多字节字符时，str_split() 会按字节数转换，而非字符数。使用 mb_str_split() 将字符串拆分为码点。

参见

mb_str_split() - 指定多字节字符串，返回其字符数组
chunk_split() - 将字符串分割成小块
preg_split() - 通过一个正则表达式分隔字符串
explode() - 使用一个字符串分割另一个字符串
count_chars() - 返回字符串所用字符的信息
str_word_count() - 返回字符串中单词的使用情况
for

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Julian ¶

1 year ago

The function str_split() is not 'aware' of words. Here is an adaptation of str_split() that is 'word-aware'.

<?php

$array =  str_split_word_aware(
    'In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep.', 
    32
);

var_dump($array);

/**
  * This function is similar to str_split() but this function keeps words intact; it never splits through a word. 
  *
  * @return array<int, string>
  */
function str_split_word_aware(string $string, int $maxLengthOfLine): array
{
    if ($maxLengthOfLine <= 0) {
        throw new RuntimeException(sprintf('The function %s() must have a max length of line at least greater than one', __FUNCTION__));
    }
    
    $lines = [];
    $words = explode(' ', $string);

    $currentLine = '';
    $lineAccumulator = '';
    foreach ($words as $currentWord) {

        $currentWordWithSpace = sprintf('%s ', $currentWord);
        $lineAccumulator .= $currentWordWithSpace;
        if (strlen($lineAccumulator) < $maxLengthOfLine) {
            $currentLine = $lineAccumulator;
            continue;
        }

        $lines[] = $currentLine;

        // Overwrite the current line and accumulator with the current word
        $currentLine = $currentWordWithSpace;
        $lineAccumulator = $currentWordWithSpace;
    }

    if ($currentLine !== '') {
        $lines[] = $currentLine;
    }

    return $lines;
}

?>

OUTPUT: 

<?php

array(5) {
  [0]=> string(29) "In the beginning God created "
  [1]=> string(30) "the heaven and the earth. And "
  [2]=> string(28) "the earth was without form, "
  [3]=> string(27) "and void; and darkness was "
  [4]=> string(27) "upon the face of the deep. "
}

?>