chr

Generate a single-byte string from a number

&reftitle.description; `string` `chr` `int` `codepoint`

Returns a one-character string containing the character specified by interpreting `codepoint` as an unsigned integer.

This can be used to create a one-character string in a single-byte encoding such as ASCII, ISO-8859, or Windows 1252, by passing the position of a desired character in the encoding's mapping table. However, note that this function is not aware of any string encoding, and in particular cannot be passed a Unicode code point value to generate a string in a multibyte encoding like UTF-8 or UTF-16.

This function complements `ord`.

&reftitle.parameters;

`codepoint`

- An integer between 0 and 255.

  Values outside the valid range (0..255) will be bitwise and'ed with 255, which is equivalent to the following algorithm:

      while ($bytevalue < 0) {
          $bytevalue += 256;
      }
      $bytevalue %= 256;

&reftitle.returnvalues;

A single-character string containing the specified byte.

&reftitle.changelog;

&Version; | &Description;
7.4.0 | The function no longer silently accepts unsupported `codepoint`s, and casts these to `0`.

&reftitle.examples;

### `chr` example

    <?php
    // Assumes the string will be used as ASCII or an ASCII-compatible encoding

    $str = "The string ends in escape: ";
    $str .= chr(27); /* add an escape character at the end of $str */

    /* Often this is more useful */

    $str = sprintf("The string ends in escape: %c", 27);
    ?>

### Overflow behavior

    <?php
    echo chr(-159), chr(833), PHP_EOL;
    ?>

&example.outputs;

    aA

### Building a UTF-8 string from individual bytes

    <?php
    $str = chr(240) . chr(159) . chr(144) . chr(152);
    echo $str;
    ?>

&example.outputs;

    🐘

&reftitle.seealso;

- `sprintf` with a format string of `%c`
- `ord`
- An ASCII-table
- `mb_chr`
- `IntlChar::chr`