Difference between float and double in php?

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105

I have this code

$vad = 1.1;



print gettype($vad);



var_dump($vad);

this will output:

double

float(1.1)

So it is double or float in php?

edited Jul 19 '10 at 12:29

Amarghosh

49.2k1078113

asked Jul 19 '10 at 12:10

Centurion

2,43962245

add a comment |

105

I have this code

$vad = 1.1;



print gettype($vad);



var_dump($vad);

this will output:

double

float(1.1)

So it is double or float in php?

edited Jul 19 '10 at 12:29

Amarghosh

49.2k1078113

asked Jul 19 '10 at 12:10

Centurion

2,43962245

add a comment |

105

I have this code

$vad = 1.1;



print gettype($vad);



var_dump($vad);

this will output:

double

float(1.1)

So it is double or float in php?

edited Jul 19 '10 at 12:29

Amarghosh

49.2k1078113

asked Jul 19 '10 at 12:10

Centurion

2,43962245

I have this code

$vad = 1.1;



print gettype($vad);



var_dump($vad);

this will output:

double

float(1.1)

So it is double or float in php?

php

edited Jul 19 '10 at 12:29

Amarghosh

49.2k1078113

asked Jul 19 '10 at 12:10

Centurion

2,43962245

edited Jul 19 '10 at 12:29

Amarghosh

49.2k1078113

asked Jul 19 '10 at 12:10

Centurion

2,43962245

edited Jul 19 '10 at 12:29

Amarghosh

49.2k1078113

edited Jul 19 '10 at 12:29

Amarghosh

49.2k1078113

edited Jul 19 '10 at 12:29

Amarghosh

49.2k1078113

asked Jul 19 '10 at 12:10

Centurion

2,43962245

asked Jul 19 '10 at 12:10

Centurion

2,43962245

asked Jul 19 '10 at 12:10

Centurion

2,43962245

add a comment |

4 Answers
4

active

oldest

votes

138

There is no difference in PHP. float, double or real are the same datatype.

At the C level, everything is stored as a double.

The real size is still platform-dependent.

See the manual for more details:
http://www.php.net/manual/en/language.types.float.php

edited Dec 11 '14 at 16:27

ratchet freak

41k44494

answered Jul 19 '10 at 12:14

Macmade

42.6k1193115

sure about that? are there some memory use diffrent about it?

– TheCrazyProfessor
Jan 1 '17 at 12:11

1

I have function function some( float $num){}, when i use some(17.23) it throws fatal error some() must be an instance of float, double given,

– NaveenDA
Sep 2 '17 at 9:02

1

@NaveenDA What version of PHP? Prior to PHP 7.0, scalar type hints were not available and would be interpreted as class names instead. That looks like what is going on there.

– Ken Wayne VanderLinde
Nov 1 '17 at 18:50

add a comment |

For PHP, they are the same. http://www.php.net/manual/en/language.types.float.php :

Floating point numbers (also known as "floats", "doubles", or "real numbers") can be specified using any of the following syntaxes: [...]

The confusing part is why gettype (which you shouldn't use, anyway) returns "double" instead of "float". The answer is http://de2.php.net/manual/en/function.gettype.php:

" double " (for historical reasons "double" is returned in case of a float , and not simply "float")

answered Jul 19 '10 at 12:19

Victor Nicollet

21.7k24587

add a comment |

As of PHP 7.0.6 on Windows, comparing this command without xdebug:

$ php -r 'var_dump(28.4);'

float(28.4)

and with xdebug:

$ php -r 'var_dump(28.4);'

Command line code:1:

double(28.4)

Note that this only changes var_dump() output, but not the actual memory management.

This may address some concerns why you see double instead of float shown in var_dump in some other machines.

Also, with or without xdebug, gettype still returns string(6) "double".

edited Dec 6 '17 at 17:22

answered Jan 14 '17 at 12:39

SOFe

2,67032144

Very interesting! Thanks for pointing this out.

– L S
Dec 6 '17 at 16:40

add a comment |

In PHP 7.0.14

function test(double $a) {

    var_dump($a);

}

test(2.2111);

Returns "Fatal error: Uncaught TypeError: Argument 1 passed to test() must be an instance of double, float given".

function test(float $a) {

    var_dump($a);

}

test(2.2111);

Prints 2.2111 to the screen.

answered Feb 22 '18 at 12:18

Oboroten

3518

1

Only float is a valid type hint (see). When you type double instead, it is treated as an class name, and interpreter throws the exception, because it expects a variable with instance of the double class

– AterLux
Oct 18 '18 at 12:24

add a comment |

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4 Answers
4

active

oldest

votes

4 Answers
4

active

oldest

votes

138

There is no difference in PHP. float, double or real are the same datatype.

At the C level, everything is stored as a double.

The real size is still platform-dependent.

See the manual for more details:
http://www.php.net/manual/en/language.types.float.php

edited Dec 11 '14 at 16:27

ratchet freak

41k44494

answered Jul 19 '10 at 12:14

Macmade

42.6k1193115

sure about that? are there some memory use diffrent about it?

– TheCrazyProfessor
Jan 1 '17 at 12:11

1

I have function function some( float $num){}, when i use some(17.23) it throws fatal error some() must be an instance of float, double given,

– NaveenDA
Sep 2 '17 at 9:02

1

@NaveenDA What version of PHP? Prior to PHP 7.0, scalar type hints were not available and would be interpreted as class names instead. That looks like what is going on there.

– Ken Wayne VanderLinde
Nov 1 '17 at 18:50

add a comment |

138

There is no difference in PHP. float, double or real are the same datatype.

At the C level, everything is stored as a double.

The real size is still platform-dependent.

See the manual for more details:
http://www.php.net/manual/en/language.types.float.php

edited Dec 11 '14 at 16:27

ratchet freak

41k44494

answered Jul 19 '10 at 12:14

Macmade

42.6k1193115

sure about that? are there some memory use diffrent about it?

– TheCrazyProfessor
Jan 1 '17 at 12:11

1

I have function function some( float $num){}, when i use some(17.23) it throws fatal error some() must be an instance of float, double given,

– NaveenDA
Sep 2 '17 at 9:02

1

@NaveenDA What version of PHP? Prior to PHP 7.0, scalar type hints were not available and would be interpreted as class names instead. That looks like what is going on there.

– Ken Wayne VanderLinde
Nov 1 '17 at 18:50

add a comment |

138

There is no difference in PHP. float, double or real are the same datatype.

At the C level, everything is stored as a double.

The real size is still platform-dependent.

See the manual for more details:
http://www.php.net/manual/en/language.types.float.php

edited Dec 11 '14 at 16:27

ratchet freak

41k44494

answered Jul 19 '10 at 12:14

Macmade

42.6k1193115

There is no difference in PHP. float, double or real are the same datatype.

At the C level, everything is stored as a double.

The real size is still platform-dependent.

See the manual for more details:
http://www.php.net/manual/en/language.types.float.php

edited Dec 11 '14 at 16:27

ratchet freak

41k44494

answered Jul 19 '10 at 12:14

Macmade

42.6k1193115

edited Dec 11 '14 at 16:27

ratchet freak

41k44494

edited Dec 11 '14 at 16:27

ratchet freak

41k44494

edited Dec 11 '14 at 16:27

ratchet freak

41k44494

answered Jul 19 '10 at 12:14

Macmade

42.6k1193115

answered Jul 19 '10 at 12:14

Macmade

42.6k1193115

answered Jul 19 '10 at 12:14

Macmade

42.6k1193115

sure about that? are there some memory use diffrent about it?

– TheCrazyProfessor
Jan 1 '17 at 12:11

1

I have function function some( float $num){}, when i use some(17.23) it throws fatal error some() must be an instance of float, double given,

– NaveenDA
Sep 2 '17 at 9:02

1

@NaveenDA What version of PHP? Prior to PHP 7.0, scalar type hints were not available and would be interpreted as class names instead. That looks like what is going on there.

– Ken Wayne VanderLinde
Nov 1 '17 at 18:50

add a comment |

sure about that? are there some memory use diffrent about it?

– TheCrazyProfessor
Jan 1 '17 at 12:11

1

I have function function some( float $num){}, when i use some(17.23) it throws fatal error some() must be an instance of float, double given,

– NaveenDA
Sep 2 '17 at 9:02

1

@NaveenDA What version of PHP? Prior to PHP 7.0, scalar type hints were not available and would be interpreted as class names instead. That looks like what is going on there.

– Ken Wayne VanderLinde
Nov 1 '17 at 18:50

sure about that? are there some memory use diffrent about it?

– TheCrazyProfessor
Jan 1 '17 at 12:11

I have function function some( float $num){}, when i use some(17.23) it throws fatal error some() must be an instance of float, double given,

– NaveenDA
Sep 2 '17 at 9:02

@NaveenDA What version of PHP? Prior to PHP 7.0, scalar type hints were not available and would be interpreted as class names instead. That looks like what is going on there.

– Ken Wayne VanderLinde
Nov 1 '17 at 18:50

add a comment |

For PHP, they are the same. http://www.php.net/manual/en/language.types.float.php :

Floating point numbers (also known as "floats", "doubles", or "real numbers") can be specified using any of the following syntaxes: [...]

The confusing part is why gettype (which you shouldn't use, anyway) returns "double" instead of "float". The answer is http://de2.php.net/manual/en/function.gettype.php:

" double " (for historical reasons "double" is returned in case of a float , and not simply "float")

answered Jul 19 '10 at 12:19

Victor Nicollet

21.7k24587

add a comment |

For PHP, they are the same. http://www.php.net/manual/en/language.types.float.php :

Floating point numbers (also known as "floats", "doubles", or "real numbers") can be specified using any of the following syntaxes: [...]

The confusing part is why gettype (which you shouldn't use, anyway) returns "double" instead of "float". The answer is http://de2.php.net/manual/en/function.gettype.php:

" double " (for historical reasons "double" is returned in case of a float , and not simply "float")

answered Jul 19 '10 at 12:19

Victor Nicollet

21.7k24587

add a comment |

For PHP, they are the same. http://www.php.net/manual/en/language.types.float.php :

Floating point numbers (also known as "floats", "doubles", or "real numbers") can be specified using any of the following syntaxes: [...]

The confusing part is why gettype (which you shouldn't use, anyway) returns "double" instead of "float". The answer is http://de2.php.net/manual/en/function.gettype.php:

" double " (for historical reasons "double" is returned in case of a float , and not simply "float")

answered Jul 19 '10 at 12:19

Victor Nicollet

21.7k24587

For PHP, they are the same. http://www.php.net/manual/en/language.types.float.php :

Floating point numbers (also known as "floats", "doubles", or "real numbers") can be specified using any of the following syntaxes: [...]

The confusing part is why gettype (which you shouldn't use, anyway) returns "double" instead of "float". The answer is http://de2.php.net/manual/en/function.gettype.php:

" double " (for historical reasons "double" is returned in case of a float , and not simply "float")

answered Jul 19 '10 at 12:19

Victor Nicollet

21.7k24587

answered Jul 19 '10 at 12:19

Victor Nicollet

21.7k24587

answered Jul 19 '10 at 12:19

Victor Nicollet

21.7k24587

answered Jul 19 '10 at 12:19

Victor Nicollet

21.7k24587

add a comment |

As of PHP 7.0.6 on Windows, comparing this command without xdebug:

$ php -r 'var_dump(28.4);'

float(28.4)

and with xdebug:

$ php -r 'var_dump(28.4);'

Command line code:1:

double(28.4)

Note that this only changes var_dump() output, but not the actual memory management.

This may address some concerns why you see double instead of float shown in var_dump in some other machines.

Also, with or without xdebug, gettype still returns string(6) "double".

edited Dec 6 '17 at 17:22

answered Jan 14 '17 at 12:39

SOFe

2,67032144

Very interesting! Thanks for pointing this out.

– L S
Dec 6 '17 at 16:40

add a comment |

As of PHP 7.0.6 on Windows, comparing this command without xdebug:

$ php -r 'var_dump(28.4);'

float(28.4)

and with xdebug:

$ php -r 'var_dump(28.4);'

Command line code:1:

double(28.4)

Note that this only changes var_dump() output, but not the actual memory management.

This may address some concerns why you see double instead of float shown in var_dump in some other machines.

Also, with or without xdebug, gettype still returns string(6) "double".

edited Dec 6 '17 at 17:22

answered Jan 14 '17 at 12:39

SOFe

2,67032144

Very interesting! Thanks for pointing this out.

– L S
Dec 6 '17 at 16:40

add a comment |

As of PHP 7.0.6 on Windows, comparing this command without xdebug:

$ php -r 'var_dump(28.4);'

float(28.4)

and with xdebug:

$ php -r 'var_dump(28.4);'

Command line code:1:

double(28.4)

Note that this only changes var_dump() output, but not the actual memory management.

This may address some concerns why you see double instead of float shown in var_dump in some other machines.

Also, with or without xdebug, gettype still returns string(6) "double".

edited Dec 6 '17 at 17:22

answered Jan 14 '17 at 12:39

SOFe

2,67032144

As of PHP 7.0.6 on Windows, comparing this command without xdebug:

$ php -r 'var_dump(28.4);'

float(28.4)

and with xdebug:

$ php -r 'var_dump(28.4);'

Command line code:1:

double(28.4)

Note that this only changes var_dump() output, but not the actual memory management.

This may address some concerns why you see double instead of float shown in var_dump in some other machines.

Also, with or without xdebug, gettype still returns string(6) "double".

edited Dec 6 '17 at 17:22

answered Jan 14 '17 at 12:39

SOFe

2,67032144

edited Dec 6 '17 at 17:22

answered Jan 14 '17 at 12:39

SOFe

2,67032144

answered Jan 14 '17 at 12:39

SOFe

2,67032144

answered Jan 14 '17 at 12:39

SOFe

2,67032144

Very interesting! Thanks for pointing this out.

– L S
Dec 6 '17 at 16:40

add a comment |

Very interesting! Thanks for pointing this out.

– L S
Dec 6 '17 at 16:40

Very interesting! Thanks for pointing this out.

– L S
Dec 6 '17 at 16:40

add a comment |

In PHP 7.0.14

function test(double $a) {

    var_dump($a);

}

test(2.2111);

Returns "Fatal error: Uncaught TypeError: Argument 1 passed to test() must be an instance of double, float given".

function test(float $a) {

    var_dump($a);

}

test(2.2111);

Prints 2.2111 to the screen.

answered Feb 22 '18 at 12:18

Oboroten

3518

1

Only float is a valid type hint (see). When you type double instead, it is treated as an class name, and interpreter throws the exception, because it expects a variable with instance of the double class

– AterLux
Oct 18 '18 at 12:24

add a comment |

In PHP 7.0.14

function test(double $a) {

    var_dump($a);

}

test(2.2111);

Returns "Fatal error: Uncaught TypeError: Argument 1 passed to test() must be an instance of double, float given".

function test(float $a) {

    var_dump($a);

}

test(2.2111);

Prints 2.2111 to the screen.

answered Feb 22 '18 at 12:18

Oboroten

3518

1

Only float is a valid type hint (see). When you type double instead, it is treated as an class name, and interpreter throws the exception, because it expects a variable with instance of the double class

– AterLux
Oct 18 '18 at 12:24

add a comment |

In PHP 7.0.14

function test(double $a) {

    var_dump($a);

}

test(2.2111);

Returns "Fatal error: Uncaught TypeError: Argument 1 passed to test() must be an instance of double, float given".

function test(float $a) {

    var_dump($a);

}

test(2.2111);

Prints 2.2111 to the screen.

answered Feb 22 '18 at 12:18

Oboroten

3518

In PHP 7.0.14

function test(double $a) {

    var_dump($a);

}

test(2.2111);

Returns "Fatal error: Uncaught TypeError: Argument 1 passed to test() must be an instance of double, float given".

function test(float $a) {

    var_dump($a);

}

test(2.2111);

Prints 2.2111 to the screen.

answered Feb 22 '18 at 12:18

Oboroten

3518

answered Feb 22 '18 at 12:18

Oboroten

3518

answered Feb 22 '18 at 12:18

Oboroten

3518

answered Feb 22 '18 at 12:18

Oboroten

3518

1

Only float is a valid type hint (see). When you type double instead, it is treated as an class name, and interpreter throws the exception, because it expects a variable with instance of the double class

– AterLux
Oct 18 '18 at 12:24

add a comment |

1

Only float is a valid type hint (see). When you type double instead, it is treated as an class name, and interpreter throws the exception, because it expects a variable with instance of the double class

– AterLux
Oct 18 '18 at 12:24

Only float is a valid type hint (see). When you type double instead, it is treated as an class name, and interpreter throws the exception, because it expects a variable with instance of the double class

– AterLux
Oct 18 '18 at 12:24

add a comment |

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