Summary of PHP Basics (iii) Process Control, functions, class objects, and databases

PHP Basic Syntax

1. Process Control

Conditional statement: If ElseIf else/switch

if ($a = =1elseif ($a = = 2)  {...} Else {...}

Looping statements: for foreach

 for($i= 1;$i<= 10;$i++) {    Echo $i;}foreach($arr  as $key=$value){//one-dimensional array looping keys and values...}foreach($arr  as $key=$value){//two-dimensional array loop key and value     foreach($value  as $value 2){//you can take a value directly in the loop...} }

2. Function:

Once written, repeated calls.

Define with Function:

function foo ($arg _1$arg _2/**/$arg _n) {     echo "Example function.\n";     return $retval ;}

Foo ($a 1, $a 2,......, $an); In PHP, the name () ==> function

There are many built-in functions, such as var_dump ()

Local variables: variables defined within a function

Global variables: Variables defined outside the function

3. Classes and objects

The class is a drawing, and the object is the house which is covered by the drawing.

Object-oriented approach: it is for larger-scale collaboration.

<?PHPclassname{ Public $a 1= 0;  Public $a 2= 1;  Public function__construct () {//Magic method, constructor without parameters,you can do it, not write it. Initial value    }     Public functionS1 () {$thisS2 ();//call the brothers and sisters with $this.    }     Public functionS2 () {Echo $this-A1; }}$name=NewName ();//class instantiationEcho $nameA2. "<br/>";//Call the Class property, "-" is the pointer to the operator, followed by the property without the $ symbol$nameS2 ();//Calling class methodsclassname2{ Public $a 1= 0;  Public $a 2= 1;  Public function__construct ($a,$b){//Constructors with parameters        $this-&GT;A1 =$a; $this-&GT;A2 =$b; }     Public functionS1 () {$this-S2 (); }     Public functionS2 () {Echo $this-A1; }}/**/$name 2=NewName2 (' A ', ' B ');Echo"<br/>" ;$name 2-S1 ();?>

Summary of PHP Basics (iii) Process Control, functions, class objects, and databases