php variable length argument

8/10/2019 PHP Variable Length Argument

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Variable Length Argument

Function

Haresh Khachariya

(Lecturer)

Shree M & N Virani Science College ,

Rajkot


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func_num_args

Returns the number of arguments passed into the

current user-defined function.

Syntax:

2

int func_num_args ( void)


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Example

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func_get_arg

Returns the argument which is at the arg_num'th

offset into a user-defined function's argument list.

Function arguments are counted starting fromzero.

Syntax:

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mixed func_get_arg ( int arg_num)


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func_get_args

It creates and returns an array which contains

values of all arguments provided in the function

call operation.

Syntax

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array func_get_args ( void)


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function fnum_args()

{$num_args = func_num_args();

echo "Number of arguments: $num_args
";

$arg_list = func_get_args();

for ($i = 0; $i < $num_args; $i++)

{echo "Argument $i is: " . $arg_list[$i] . "
\n";

}

} fnum_args(1, 2, 3); ?> 7


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Variable Function

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gettype()

The gettype() function return the type of a

variable.

Syntax:

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gettype(var_name)


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Example

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settype()

The settype() function is used to set the type of

a variable.

Return TRUE on success or FALSE on failure.

Syntax:

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settype(var_name, var_type)

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Example $var1='98'; $var2='01'; $var3=10; $var4=true;

settype($var1, "integer"); settype($var2, "integer");

settype($var3, "string"); settype($var4, "null");

echo ($var1.'
'); echo ($var2.'
');

echo ($var1+$var2.'
');

echo gettype($var3)."
"; echo gettype($var4);

?>

Output

98 1 99 string NULL 12


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isset ()

The isset () function is used to check whether a value

of variable is set or not.

The isset() function return false if testing variable

contains a NULL value or unset using unset()function and return true if testing variable contains

values or set.

Syntax:

13isset(variable1)

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Example

Output

bool(true) bool(false) bool(false)

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unset()

The unset() function destroys a given variableor unset the given variable.

Syntax:

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unset (var1)


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Example

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strval()

The strval() is used to convert a value of avariable to a string.

Syntax:

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strval(var_name)


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Example

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intval()

The intval() function is used to get the integervalue of a variable.

Syntax:

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intval(var_name)


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Example

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floatval()

The floatval() function is used to convert a valueto a float.

Syntax:

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floatval (var1)


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Example

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print_r()

The print_r() function is used to print value of

variable or array with returns keys and elements

information.

Syntax:

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print_r(var_name, return_output)


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echo()

The echo() function outputs one or more strings.

Syntax:

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echo(strings)


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Difference Between Echo And Print_r

echo is used to output and display single types

(strings, ints, etc).

echo is a statement.

echo is a raw language construct print_r is used to output and display the contents of an

array.

while print is a function.

print_r is functions with return values.

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File handling Function

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fopen()

The fopen() function is used to open files in PHP.

The first parameter of this function contains the

name of the file to be opened and the secondparameter specifies in which mode the file should

be opened.

If fopen is unable to open the file, it returns 0

(zero) otherwise it will return 1.

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Syntax and Example

var_name=fopen(file_name,file_open_mode)


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The file may be opened in one of the following modes

Modes Description

r Read only. Starts at the beginning of the filer+ Read/Write. Starts at the beginning of the file

w Write only. Opens and clears the contents of

file; or creates a new file if it doesn't exist

w+ Read/Write. Opens and clears the contents of

file; or creates a new file if it doesn't exist

a Append. Opens and writes to the end of the

file or creates a new file if it doesn't exist

a+ Read/Append. Preserves file content by

writing to the end of the file

x Write only. Creates a new file. ReturnsFALSE and an error if file already exists

x+ Read/Write. Creates a new file. Returns

FALSE and an error if file already exists

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fwrite()

The fwrite function allows data to be written to

any type of file and an open file.

The function will stop at the end of the file orwhen it reaches the specified length, whichever

comes first.

This function returns the number of bytes written

on success, or FALSE on failure.

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Syntax and Example

var_name =fwrite(file,string,length)


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fread()

The fread() reads from an open file.

The function will stop at the end of the file or

when it reaches the specified length, whichevercomes first.

fread() function returns the read string on success,or FALSE on failure.

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Syntax and Example

Syntax:


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fclose()

The fclose() function closes an open file.

fcose() function returns TRUE on success or

FALSE on failure.

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Syntax and Example

Syntax:

fclose(file)


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file_exists()

file_exists() function is used to check whether a

file or directory exists or not.

Return TRUE if the file or directory specifiedby file_name exists otherwise FALSE.

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Syntax and Example

Syntax:

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var_name=file_exists (file_name)

i d bl


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is_readable

The is_readable() function is used to check whether

the specified file is readable or not.

TRUE if file_name exists and is readable, FALSE

otherwise.

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d l


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Syntax and Example

is_readable(file_name)

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bl ()


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is_writable()

The is_writable() function is used to check whether

the specified file is writeable.

TRUE if file_name exists and is writable.

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S d E l


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Syntax and Example

is_writable(file_name)

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f ()


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fgets()

The fgets() function is used to get line from file

pointer of an open file.

The fgets() function stops returning on a new line, atthe specified length, or at EOF, whichever comes

first.

This function returns FALSE on failure.

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S d E l


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Syntax and Example

fgets(file_handler, byte_length)

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Name Descriptionfile_handler When a file is successfully opened by fopen() or

fsockopen() it returns a resource ID, which isreferred as file handler or file pointer. The fgets()function uses this ID to return a series of bytes

from an open filebyte_length Specifies the number of bytes to read. Default

length is 1024.


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f t ()


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fgetc()

The fgetc() function reads a single character from a

open file pointed by file handler..

A string containing a single character and FALSE onEOF.

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S t d E l


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Syntax and Example

fgetc(file_handler)

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fil ()


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file()

The file() reads whole file into an array.

Each array element contains a line from the file, with

newline still attached.

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S t d E l


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Syntax and Example

file(path,include_path,context)

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fil t t t ()


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file_get_contents()

The file_get_contents() reads a whole file into a

string.

file_get_contents (file_name, include_path_name, context,

star_position, max_length)

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Parameter Description

path Required. Specifies the file to read

include_path Optional. Set this parameter to '1' if you want to search for

the file in the include_path (in php.ini) as well

context Optional. Specifies the context of the file handle. Context is a

set of options that can modify the behavior of a stream. Can

be skipped by using NULL.

start Optional. Specifies where in the file to start reading. Thisparameter was added in PHP 5.1

max_length Optional. Specifies how many bytes to read. This parameter

was added in PHP 5.1

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E ample


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Example

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file putcontents()


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file_putcontents()

The file_put_contents() function writes a string

to a file.

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file_put_contents(file,data,mode,context)

Syntax and Example


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Syntax and Example


file Required. Specifies the file to write to. If the file does notexist, this function will create one

data Required. The data to write to the file. Can be a string, an array or adata stream

mode Optional. Specifies how to open/write to the file. Possible values:

FILE_USE_INCLUDE_PATHFILE_APPENDLOCK_EX

context Optional. Specifies the context of the file handle. Context is a set ofoptions that can modify the behavior of a stream.

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ftell()


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ftell()

The ftell() function is used to fetch the current

position of the file pointer of an open file.

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ftell(file_handler)

Example


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Example

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fseek()


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fseek()

The fseek() function is used to move the file pointer

in an open file.

This function moves the file pointer from its current

position to a new position, forward or backward,

specified by the number of bytes.

This function returns 0 on success, or -1 on failure.

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Syntax and Example


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Syntax and Example

fseek(file,offset,whence)

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file Required. Specifies the open file to seek in

offset The the number of bytes to move the file pointer.

whence Optional. (added in PHP 4). Possible values:

SEEK_SET - Set position equal to offset.DefaultSEEK_CUR - Set position to current locationplus offsetSEEK_END - Set position to EOF plus offset (tomove to a position before EOF, the offset mustbe a negative value)


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Atmiya College Rajkot Comp. Dept.

0

iya College Rajkot Comp. Dept.

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rewind()


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rewind()

The rewind() function is used to set the file pointer to

the beginning of the file.

This function returns TRUE on success, or FALSE on

failure.

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Syntax and Example


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Syntax and Example

rewind (file_handler)

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copy()


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copy()

The copy() function copies a file from source to

destination.

This function returns TRUE on success and FALSE

on failure.

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Syntax and Example


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Syntax and Example

copy(source, destination)

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unlink()


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unlink()

The unlink() function deletes a file.


failure.

unlink(filename)

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Example


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Example

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rename()


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rename()

The rename() function renames directory or a

file.

rename(old_filename, new_filename, context)

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move uploaded file()


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move_uploaded_file()

The move_uploaded_file() function moves an

uploaded file to a new location.


failure.

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Syntax


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Syntax

move_uploaded_file(file,newloc)

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file Required. Specifies the file to be movednewloc Required. Specifies the new location for the file

Example


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Example

$target_path = "img/".$_FILES['image1']['name'];

if(move_uploaded_file($_FILES['image1']['tmp_name'],

$target_path))

{

echo "File is uploaded";

}

else

{ echo "File isnot uploaded"; }

?>69


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Questions?

php variable length argument

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