Call a function or method from inside its class

问题

I have written a database class but can't access the method from within:

class database{
.
.
private $mgc;
private $real;
public function insert($table,$values,$row = null){
.
.
 for($i = 0; $i < count($values); $i++){
    $values[$i] = safe_value ($values[$i]);      
    } 
.
.
}
public function safe_value( $value ) {
    if( $this->real ) {  
        if( $this->mgc ) { $value = stripslashes( $value ); }
        $value = mysql_real_escape_string( $value );
    } 
    else {  

        if( !$this->mgc ) { $value = addslashes( $value ); }

    }
    return $value;
} 

}

When running this class I have this error:

Fatal error: Call to undefined function safe_value()

When I used mysql_real_escape_string instead of the safe_value method the class works perfectly. Why can't I access the safe_value function and why is it showing me this error?

回答1:

When calling a non-static member function from within the class you need to refer to it using $this, in this particular case you should call it as

$values[$i] = $this->safe_value($values[$i]);

回答2:

You need to change the call to $values[$i] = $this->safe_value($values[$i]); for non-static methods. For static methods, use $values[$i] = database::safe_value($values[$i]).

来源：https://stackoverflow.com/questions/4115753/call-a-function-or-method-from-inside-its-class