---
name: "JSON::Types"
section: "3pm"
platform: "linux"
package: "libjson-types-perl"
version: "0.05-4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/JSON::Types"
---

# JSON::Types(3pm)

variable type utility for JSON encoding

## NAME

JSON::Types - variable type utility for JSON encoding

## SYNOPSIS

```
    # Export type functions by default
    use JSON;
    use JSON::Types;

    print encode_json({
        number => number "123",
        string => string 123,
        bool   => bool "True value",
    });
    # => {"number":123,"string":"123","bool":true}

    # Non export interface
    use JSON::Types ();

    print encode_json({
        number => JSON::Types::number "123",
        string => JSON::Types::string 123,
        bool   => JSON::Types::bool "True value",
    });
```

## DESCRIPTION

The type mappings between JSON and Perl is annoying things. For example,

```
    use JSON;

    my $number = 123;

    warn "[DEBUG] number:$number\n" if $ENV{DEBUG};

    print encode_json([ $number ]);
```

Output of this code depends on whether DEBUG environment is set or not. If set, result is `"[123]"`. If not to set, result is `"["123"]"`. This is normal behaviour on Perl though, it sometimes causes unexpected JSON results.

There is a solution about this:

```
    print encode_json([ $number + 0 ]);
```

This code always outputs `"[123]"`. But the code is a bit ugly and not readable at all.

This module provides some functions to fix this variable types issue:

```
    number $foo;  # is always number
    string $foo;  # is always string
    bool   $foo;  # is always bool
```

You can fix above code by using this module like this:

```
    use JSON;
    use JSON::Types;

    my $number = 123;

    warn "[DEBUG] number:$number\n" if $ENV{DEBUG};

    print encode_json([ number $number ]);
```

## FUNCTIONS

There is three functions and all functions is exported by default.

If you don't want this exported functions, pass empty list to use line:

```
    use JSON::Types ();
```

You should specify full function name when this case, like `"JSON::Types::number $foo"` or etc.

### string

### number

### bool

## BEHAVIOURS ON UNEXPECTED ARGS

### string(undef), number(undef) returns undef, bool(undef) returns false.

Passing undefined variable to string and number function is returns undef. If you doesn't prefer this, have to treat this like following:

```
    number $undef_possible_value // 0
```

This code returns 0 if variable is undef.

### number($string)

Passing not numeric variable to number function is returns 0, but a warning will be occurred.

## AUTHOR

Daisuke Murase \<typester@cpan.org\>

## COPYRIGHT AND LICENSE

Copyright (c) 2012 Daisuke Murase. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

The full text of the license can be found in the LICENSE file included with this module.