How to pass values ​​to variables in PHP? How to deliver?

We have learned so much about PHP. What is the value transfer method of variables in PHP today? How to deliver? , I wonder if you have fully mastered it. If not, then follow this article to continue learning.

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The value-passing method of variables:

1, the value-passing method of variables is Refers to the internal detailed form of "passing one variable to another variable" - one-to-one;

2, the value-passing method of variables, there are only 2: value passing, reference passing;

Value transfer:

Sv1= 1;

$v2=Sv1; 1/This is value transfer

Simple understanding: Sv1 Take out the value (note: the value in Sv1 is still there), and then use this value to assign a value to $v2.

Image understanding:

Visible , Value transfer means that the value of variable v1 is copied, and then assigned to another variable v2.

Note:

1The two variables are equal in value at this time1

2The two variables are independent of each other - do not affect each other;

That is, Sv1=10; then echo $v2, //Output 1

The code is as follows:

<?php
$v1 =1;
$v2 = $v1; //值传递:
$v1=10;
echo "<br />v2 = $v2";//1
?>

The running results are as follows:

Pass by reference:

In PHP, there is only one syntax form that can realize the reference-value transfer of variables: the & symbol.

An example is as follows!

$ml=1;
$m2 = &$ml; //引用传值方式

Simple understanding: Copy the "reference relationship" between variable $m1 and its data values, and then give it to transaction $m2, that is, at this time , the variable $m2 also has a "reference relationship" (pointing relationship) with the original data,

The result is:

1, at this time there are still 2 variables, but only one Data value (data space), both variables point to this data space.

2. The operation of any of the variables is actually manipulating the data value (space).

<?php
$v1 = 1;
$v2 = $v1; //值传递:
$v1 = 10;
echo "<br />v1 = $v1";//10
echo "<br />v2 = $v2";//1
echo "<hr />";
$m1 = 1;
$m2 =& $m1;//引用传值方式
$m1 = 10;
echo "<br />m1 =$m1";//10
echo "<br />m2 = $m2";//10
?>
</body>
</html>

The code is as follows:

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