PHP array processing function extract and instance code _php instance

PHP Array processing function extract

The extract function is used to import variables from an array into the current symbol table

Basic syntax

int Extract (array & $var _array [, int $extract _type = extr_overwrite [, String $prefix = NULL]])

This function is used to import variables from the array into the current symbol table. Check each key name to see if it can be used as a valid variable name and also check for conflicts with the variable names already in the symbol table.

Parameter description:

Parameters	Description
Var_array	Necessary. Specifies the array to use. An associative array. This function treats the key name as the variable name, and the value as the value of the variable. For each key/value pair, the variables are created in the current symbol table and are affected by the Extract_type and prefix parameters. You must use associative arrays, and arrays of numeric indexes will not produce results unless you use Extr_prefix_all or Extr_prefix_invalid.
Extract_type	Optional. The extract () function checks to see if each key name is a valid variable name, and also checks to see if the variable name already exists in the symbol table conflicts. The handling of non-law and conflicting key names is determined by this parameter. Possible values: Extr_overwrite-Default. If there is a conflict, overwrite the existing variable. Extr_skip-If there is a conflict, do not overwrite the existing variable. Extr_prefix_same-If there is a conflict, precede the variable name with the prefix PREFIX. Extr_prefix_all-Prefix all variable names with PREFIX. Extr_prefix_invalid-Prefix PREFIX only before the illegal or numeric variable name. Extr_if_exists-Overrides the value of a variable with the same name in the current symbol table only. None of the others will deal with it. Extr_prefix_if_exists-A variable name with the prefix appended to it is created only if a variable with the same name already exists in the current symbol table, and none of the others are processed. Extr_refs-Extracts the variable as a reference. The imported variable still references the value of the array parameter.
Prefix	Optional. Note Prefix only the value in Extract_type is Extr_prefix_same, Extr_prefix_all, Extr_prefix_invalid, or extr_prefix_if_exists is required. If the result appended with the prefix is not a valid variable name, it will not be imported into the symbol table. An underscore is automatically added between the prefix and the array key name.

return value

Returns the number of variables successfully imported into the symbol table.

Instance:

<?php$size = "large"; $var _array = Array (  "color" = "Blue",  "size" = "Medium",  
";? >  

Operation Result:

Blue, large, sphere, medium

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