Php net array to string

PHP: How to Convert Array to String using implode()

PHP comes with its native function to convert Array to string called implode().

The implode() function has two implementation:

The implode() function that accepts two arguments — String used to join array elements & Array itself Example: Here we will join array elements using «, » to store it as comma separated values.

$arr = ['Thor','Captain America','Iron Man']; echo implode(', ',$arr); // "Thor, Captain America, Iron Man"

$arr = ['H','e','l','l','o']; echo implode($arr); // "Hello"

Note: If the PHP array contains non-string items, implode function will first convert it to string and use it in the joined string. Boolean values are representated as → true = 1, false = 0.

Convert PHP Associative Array to String using implode()

The implode() function can not only join arrays with integer index but with string index as well, which we call it as associative arrays.

There are two approaches to this:

1) Combine only values to string

This is very simple since implode() function only considers array item’s value and not index. So, you can use implode() function directly like below:

$users = [ 'user1' => 'user1@example.com', 'user2' => 'user2@example.com' ]; echo implode(', ',$users); // "user1@example.com, user2@example.com"

2) Combine both Index and value to string

If you want to use both values and index while joining array to string, then it gets complex. There are many ways to achieve this. Also, it depends how you want to represent the index and values in string. The implode() doesn’t have any native functionality to handle such situations therefore, we will use multiple PHP functions including implode() function to achieve the same.

Example: Using the same associative array shown above, we will use both index and value i.e username and email address and combine it as follow:

$users = [ 'user1' => 'user1@example.com', 'user2' => 'user2@example.com' ]; $flattened = $array; array_walk($flattened, function(&$value, $key)  $value = "$key>:$value>"; >); echo implode(', ', $flattened); // "user1:user1@example.com, user2:user2@example.com"

In above example, we are combining username and email via color (:) by applying our custom function to each element in array using array_walk and then using implode(), we convert it to string.

Convert PHP Array of Arrays to String using implode()

Array can not only hold primary data types but Arrays and objects as well. If your Array holds arrays then combining all items at sub-level can get tricky.

The implode() cannot combine items at sub-level, therefore it doesn’t work with array of arrays directly.

Example: Notice here , implode() method only considers top-level items and while converting items to string, it returns «Array» as string.

$users = [ 'users' => ['user1@example.com','user2@example.com'], 'admins' => ['admin1@example.com', 'admin2@example.com'] ]; echo implode(', ',$users); // Array, Array 

There are different ways to achieve this and depends on what kind the array is. For our simple example above, easiest approach would be to loop-through the array to retrive each sub-array and join them.

$users = [ 'users' => ['user1@example.com','user2@example.com'], 'admins' => ['admin1@example.com', 'admin2@example.com'] ]; // function to convert array of arrays to string function implodeArrayofArrays($array, $glue = ', ')  $output = ''; foreach ($array as $subarray)  $output .= implode($separator, $subarray); > return $output; > echo implodeArrayofArrays($users); // "user1@example.com, user2@example.com, admin1@example.com, admin2@example.com"

But, if your arrays has more levels — multidimensional array then you will have to check whether the item is of Array type or not. If it is then loop through that array as well.

Convert PHP Array to String using json_encode() and serialize()

There are other ways to convert PHP arrays to string as well. We will explore two methods to convert array to string in PHP. These functions even though returns string, have different purpose.

1) json_encode()

This function is very useful to not only convert PHP array to strings but pass it to javascript as well. You cannot pass PHP arrays to JavaScript directly, so you can convert it to JSON string using json_encode() and use it in JavaScript efficiently.

$arr = ['Thor','Captain America','Iron Man']; echo json_encode($arr); // "['Thor','Captain America','Iron Man']"

2) serialize()

This function is helpful when you want to convert PHP array into storable representation. Like, when you want to store PHP array in a memory buffer, this function can be helpful.

$arr = ['Thor','Captain America','Iron Man']; echo serialize($arr); // a:3: 

That’s all for today! Keep Learning

Источник

strval

Get the string value of a variable. See the documentation on string for more information on converting to string.

This function performs no formatting on the returned value. If you are looking for a way to format a numeric value as a string, please see sprintf() or number_format() .

Parameters

The variable that is being converted to a string .

value may be any scalar type, null , or an object that implements the __toString() method. You cannot use strval() on arrays or on objects that do not implement the __toString() method.

Return Values

The string value of value .

Examples

Example #1 strval() example using PHP magic __toString() method.

class StrValTest
public function __toString ()
return __CLASS__ ;
>
>

// Prints ‘StrValTest’
echo strval (new StrValTest );
?>

See Also

• boolval() — Get the boolean value of a variable
• floatval() — Get float value of a variable
• intval() — Get the integer value of a variable
• settype() — Set the type of a variable
• sprintf() — Return a formatted string
• number_format() — Format a number with grouped thousands
• Type juggling
• __toString()

User Contributed Notes 9 notes

As of PHP 5.2, strval() will return the string value of an object, calling its __toString() method to determine what that value is.

Some notes about how this function has changed over time, with regards the following statement:

> You cannot use strval() on arrays or on objects that
> do not implement the __toString() method.

In PHP 5.3 and below, strval(array(1, 2, 3)) would return the string «Array» without any sort of error occurring.

From 5.4 and above, the return value is unchanged but you will now get a notice-level error: «Array to string conversion».

For objects that do not implement __toString(), the behaviour has varied:

PHP 4: «Object»
PHP 5 < 5.2: "Object id #1" (number obviously varies)
PHP >= 5.2: Catchable fatal error: Object of class X could not be converted to string

If you want to convert an integer into an English word string, eg. 29 -> twenty-nine, then here’s a function to do it.

Note on use of fmod()
I used the floating point fmod() in preference to the % operator, because % converts the operands to int, corrupting values outside of the range [-2147483648, 2147483647]

I haven’t bothered with «billion» because the word means 10e9 or 10e12 depending who you ask.

The function returns ‘#’ if the argument does not represent a whole number.

$nwords = array( «zero» , «one» , «two» , «three» , «four» , «five» , «six» , «seven» ,
«eight» , «nine» , «ten» , «eleven» , «twelve» , «thirteen» ,
«fourteen» , «fifteen» , «sixteen» , «seventeen» , «eighteen» ,
«nineteen» , «twenty» , 30 => «thirty» , 40 => «forty» ,
50 => «fifty» , 60 => «sixty» , 70 => «seventy» , 80 => «eighty» ,
90 => «ninety» );

function int_to_words ( $x ) global $nwords ;

if(! is_numeric ( $x ))
$w = ‘#’ ;
else if( fmod ( $x , 1 ) != 0 )
$w = ‘#’ ;
else if( $x < 0 ) $w = 'minus ' ;
$x = — $x ;
> else
$w = » ;
// . now $x is a non-negative integer.

if( $x < 21 ) // 0 to 20
$w .= $nwords [ $x ];
else if( $x < 100 ) < // 21 to 99
$w .= $nwords [ 10 * floor ( $x / 10 )];
$r = fmod ( $x , 10 );
if( $r > 0 )
$w .= ‘-‘ . $nwords [ $r ];
> else if( $x < 1000 ) < // 100 to 999
$w .= $nwords [ floor ( $x / 100 )] . ‘ hundred’ ;
$r = fmod ( $x , 100 );
if( $r > 0 )
$w .= ‘ and ‘ . int_to_words ( $r );
> else if( $x < 1000000 ) < // 1000 to 999999
$w .= int_to_words ( floor ( $x / 1000 )) . ‘ thousand’ ;
$r = fmod ( $x , 1000 );
if( $r > 0 ) $w .= ‘ ‘ ;
if( $r < 100 )
$w .= ‘and ‘ ;
$w .= int_to_words ( $r );
>
> else < // millions
$w .= int_to_words ( floor ( $x / 1000000 )) . ‘ million’ ;
$r = fmod ( $x , 1000000 );
if( $r > 0 ) $w .= ‘ ‘ ;
if( $r < 100 )
$word .= ‘and ‘ ;
$w .= int_to_words ( $r );
>
>
>
return $w ;
>

?>

Usage:
echo ‘There are currently ‘ . int_to_words ( $count ) . ‘ members logged on.’ ;
?>

I can’t help being surprised that

evaluates to true. It’s the same with strval and single quotes.
=== avoids it.

Why does it matter? One of my suppliers, unbelievably, uses 0 to mean standard discount and 0.00 to mean no discount in their stock files.

The only way to convert a large float to a string is to use printf(‘%0.0f’,$float); instead of strval($float); (php 5.1.4).

// strval() will lose digits around pow(2,45);
echo pow(2,50); // 1.1258999068426E+015
echo (string)pow(2,50); // 1.1258999068426E+015
echo strval(pow(2,50)); // 1.1258999068426E+015

// full conversion
printf(‘%0.0f’,pow(2,50)); // 112589906846624
echo sprintf(‘%0.0f’,pow(2,50)); // 112589906846624

It seems that one is being treated as an unsigned large int (32 bit), and the other as a signed large int (which has rolled over/under).

2326201276 — (-1968766020) = 4294967296.

As of PHP 5.1.4 (I have not tested it in later versions), the strval function does not attempt to invoke the __toString method when it encounters an object. This simple wrapper function will handle this circumstance for you:

/**
* Returns the string value of a variable
*
* This differs from strval in that it invokes __toString if an object is given
* and the object has that method
*/
function stringVal ($value)
// We use get_class_methods instead of method_exists to ensure that __toString is a public method
if (is_object($value) && in_array(«__toString», get_class_methods($value)))
return strval($value->__toString());
else
return strval($value);
>

In complement to Tom Nicholson’s contribution, here is the french version (actually it’s possible to change the language, but you should check the syntax 😉 )

function int_to_words($x) global $nwords;

if(!is_numeric($x))
$w = ‘#’;
else if(fmod($x, 1) != 0)
$w = ‘#’;
else if($x < 0) $w = $nwords['minus'].' ';
$x = -$x;
> else
$w = »;
// . now $x is a non-negative integer.

if($x < 21) // 0 to 20
$w .= $nwords[$x];
else if($x < 100) < // 21 to 99
$w .= $nwords[10 * floor($x/10)];
$r = fmod($x, 10);
if($r > 0)
$w .= ‘-‘. $nwords[$r];
> else if($x < 1000) < // 100 to 999
$w .= $nwords[floor($x/100)] .’ ‘.$nwords[‘hundred’];
$r = fmod($x, 100);
if($r > 0)
$w .= ‘ ‘.$nwords[‘separator’].’ ‘. int_to_words($r);
> else if($x < 1000000) < // 1000 to 999999
$w .= int_to_words(floor($x/1000)) .’ ‘.$nwords[‘thousand’];
$r = fmod($x, 1000);
if($r > 0) $w .= ‘ ‘;
if($r < 100)
$w .= $nwords[‘separator’].’ ‘;
$w .= int_to_words($r);

>
> else < // millions
$w .= int_to_words(floor($x/1000000)) .’ ‘.$nwords[‘million’];
$r = fmod($x, 1000000);
if($r > 0) $w .= ‘ ‘;
if($r < 100)
$word .= $nwords[‘separator’].’ ‘;
$w .= int_to_words($r);
>
>
>
return $w;
>

// Usage in English
$nwords = array( «zero», «one», «two», «three», «four», «five», «six», «seven»,
«eight», «nine», «ten», «eleven», «twelve», «thirteen»,
«fourteen», «fifteen», «sixteen», «seventeen», «eighteen»,
«nineteen», «twenty», 30 => «thirty», 40 => «forty»,
50 => «fifty», 60 => «sixty», 70 => «seventy», 80 => «eighty»,
90 => «ninety» , «hundred» => «hundred», «thousand»=> «thousand», «million»=>»million»,
«separator»=>»and», «minus»=>»minus»);

echo ‘There are currently ‘. int_to_words(-120223456) . ‘ members logged on.
‘;

//Utilisation en Francais
$nwords = array( «zéro», «un», «deux», «trois», «quatre», «cinq», «six», «sept»,
«huit», «neuf», «dix», «onze», «douze», «treize»,
«quatorze», «quinze», «seize», «dix-sept», «dix-huit»,
«dix-neuf», «vingt», 30 => «trente», 40 => «quarante»,
50 => «cinquante», 60 => «soixante», 70 => «soixante-dix», 80 => «quatre-vingt»,
90 => «quatre-vingt-dix» , «hundred» => «cent», «thousand»=> «mille», «million»=>»million»,
«separator»=>»», «minus»=>»moins»);

echo ‘Il y a actuellement ‘. int_to_words(-120223456) . ‘ membres connectés.
‘;

Источник