How to echo variable from the class function to the other file

问题

I am just a beginner at OOP PHP. What I want to happen is to echo the variable from the class inside the function to other file. Please take a look at this code:

in class.library.php file:

class db_connect {

    // Other functions and variables here

    function settings() {
        $sql="SELECT * FROM lms_admin_settings";
        $result = $this->conn->query($sql);
        while($data = $result->fetch_assoc()) {
            $name = $data["name"];
        }
    }
}

and in index.php file:

include("class.library.php");
$data = new db_connect;
$data->settings();

what I want to happen is to simply echo the variable named $name from settings() function of class named db_connect to index.php file.

I tried something like this:

include("class.library.php");
$data = new db_connect;
$data->settings();
echo $name; // I tried this but didn't work, I put this just to make things more clearly.

Please tell me the correct way of doing that.

PS: Pardon for what terms that I've used to explain my problem. I am just a beginner. You are always welcome to correct me.

回答1:

You need to set $name as a public var into your class. Like this:

class db_connect {
    // We declare a public var
    public $name = "";

    function settings() {
        $sql="SELECT * FROM lms_admin_settings";
        $result = $this->conn->query($sql);
        while($data = $result->fetch_assoc()) {
            $this->name = $data["name"];
        }
    }
}

Then you should be able to access your var like this in index.php:

$data = new db_connect;
$data->settings();
echo $data->name;

You can read this to learn more about vars and function visibility Php doc

回答2:

The problem is, you're not returning anything from the settings() method. Return the entire result set from the settings() method and loop through it, like this:

class.library.php

class db_connect {

    // Other functions and variables here

    function settings() {
        $sql="SELECT * FROM lms_admin_settings";
        $result = $this->conn->query($sql);
        return $result;
    }
}

index.php

include("class.library.php");
$data = new db_connect;

// catch the result set
$result = $data->settings();

// loop through the result set
while($data = $result->fetch_assoc()) {
    // display
    echo $data['name'] . "<br />";
}

回答3:

<?php

class db_connect {

    // Other functions and variables here
    public $name;
    function settings() {

        $sql="SELECT * FROM lms_admin_settings";
        $result = $this->conn->query($sql);

        while($data = $result->fetch_assoc()) {
            $this->name = $data["name"];
        }
    }
}

//index.php
include("class.library.php");
$data = new db_connect;
$data->settings();
echo($data->name);

?>

来源：https://stackoverflow.com/questions/35091778/how-to-echo-variable-from-the-class-function-to-the-other-file

标签

php

oop

echo