# grapheme_substr

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.0)

grapheme_substrReturn part of a string

### 说明

grapheme_substr ( string `\$string` , int `\$start` [, int `\$length` ] ) : string

Return part of a string

### 参数

`string`

The input string. Must be valid UTF-8.

`start`

Start position in default grapheme units. If \$start is non-negative, the returned string will start at the \$start'th position in \$string, counting from zero. If \$start is negative, the returned string will start at the \$start'th grapheme unit from the end of string.

`length`

Length in grapheme units. If \$length is given and is positive, the string returned will contain at most \$length grapheme units beginning from \$start (depending on the length of string). If \$length is given and is negative, then that many grapheme units will be omitted from the end of string (after the start position has been calculated when a start is negative). If \$start denotes a position beyond this truncation, `FALSE` will be returned.

### 返回值

Returns the extracted part of \$string.

### 更新日志

5.4 If `length` is given and positive and the argument string is shorter than the specified length, all the rest of the string according to `start` parameter is returned. Previously, `FALSE` was returned.

### 范例

Example #1 grapheme_substr() example

``` <?php\$char_a_ring_nfd = "a\xCC\x8A";  // 'LATIN SMALL LETTER A WITH RING ABOVE' (U+00E5) normalization form "D"\$char_o_diaeresis_nfd = "o\xCC\x88"; // 'LATIN SMALL LETTER O WITH DIAERESIS' (U+00F6) normalization form "D"print urlencode(grapheme_substr( "ao" . \$char_a_ring_nfd . "bc" . \$char_o_diaeresis_nfd . "O", 2, -1 ));?> ```

```a%CC%8Abco%CC%88
```

### 参见
{"ft_lang_label":"__label__en","ft_lang_prob":0.718765,"math_prob":0.8686605,"size":1573,"snap":"2020-10-2020-16","text_gpt3_token_len":452,"char_repetition_ratio":0.15041427,"word_repetition_ratio":0.04819277,"special_character_ratio":0.26954862,"punctuation_ratio":0.13993174,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.97592556,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-02-28T00:54:55Z\",\"WARC-Record-ID\":\"<urn:uuid:eb5aa82a-8e9a-460d-9d1c-c242a779694a>\",\"Content-Length\":\"24217\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:d78b94ff-ac6d-400c-ab28-2eaf56fc68f2>\",\"WARC-Concurrent-To\":\"<urn:uuid:90ef6a37-7120-49b8-96f2-8d01d070ae03>\",\"WARC-IP-Address\":\"185.85.0.29\",\"WARC-Target-URI\":\"https://www.php.net/manual/zh/function.grapheme-substr.php\",\"WARC-Payload-Digest\":\"sha1:QMVXV4KCGGCUNYPFNW5ZL4Z2EZJID6WA\",\"WARC-Block-Digest\":\"sha1:Q7VQRZFGDYRLJXY4ZQ2MWJ67WKTG3UNC\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-10/CC-MAIN-2020-10_segments_1581875146907.86_warc_CC-MAIN-20200227221724-20200228011724-00538.warc.gz\"}"}