PHP extract() function usage php array splitting-PHP Tutorial-php.cn

PHP extract() function usage php array splitting

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Release： 2016-07-25 08:54:09

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In action.php, just use the extract() function to extract the $_POST global data: action.php

extract($_POST);
//Equivalent to $username = $_POST['username'];
//$password = $_POST['password'];
?> ;

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Explanation in php manual:

extract (PHP 4, PHP 5)

extract — Import variables from an array into the current symbol table

Instructions int extract (array $var_array [, int $extract_type [, string $prefix ]] )

This function is used to import variables from the array into the current symbol table. Accepts the associative array var_array as argument and uses the key name as the variable name and the value as the variable value. For each key/value pair a variable is created in the current symbol table, affected by the extract_type and prefix parameters.

Note: Since version 4.0.5 this function returns the number of variables extracted.

Note: EXTR_IF_EXISTS and EXTR_PREFIX_IF_EXISTS were introduced in version 4.2.0.

Note: EXTR_REFS was introduced in version 4.3.0.

extract() checks each key name to see if it can be used as a legal variable name, and also checks for conflicts with existing variable names in the symbol table. The treatment of illegal/numeric and conflicting key names will be determined by the extract_type parameter. Can be one of the following values:

/* Assume $var_array is the array returned by wddx_deserialize*/
$size = "large";
$var_array = array("color" => "blue",
"size ” => “medium”,
“shape” => “sphere”);
extract($var_array, EXTR_PREFIX_SAME, “wddx”);
echo “$color, $size, $shape, $wddx_sizen”;
?>

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The output of the above example: blue, large, sphere, medium

$size is not overridden because EXTR_PREFIX_SAME is specified, which causes $wddx_size to be built. If EXTR_SKIP is specified, $wddx_size will not be created either. EXTR_OVERWRITE will make $size have the value "medium" and EXTR_PREFIX_ALL will create new variables $wddx_color, $wddx_size and $wddx_shape.

Associative arrays must be used, numerically indexed arrays will not produce results unless EXTR_PREFIX_ALL or EXTR_PREFIX_INVALID is used.