1 PHP Statement Constructs Server Scripting

5-2 Basic Statement All Statements end in a semicolon. Statements are delimited from the HTML code by enclosing the code between Echo command is used to put text directly in the web page. PHP code is mixed with the HTML code Comments in PHP are delimited by Either // for a comment on one line /* and */ for blocks of comments.

5-3 Declaration of variables Syntax var $variablename; Variables in PHP start with a dollar sign ("$"). The value that a variable holds can be changed any time at all. Var $myname = “Fred”;

5-4 Constants Syntax define (“Constant_Name”,”value”) Define (“Const tax_rate”, 0.07) The values maybe an integer, floating point or a string.

5-5 Declaring arrays Syntax  $variable = array (val1, val2, …, valn);  $light = array (“red”, “yellow”, “green”); To reference a specific element in the array  $variable[pointervalue]—use parenthesis The first position in an array is position 0.

5-6 Operators Arithmetic operators are the same Relational Operators == -- one equal sign for equal comparison != -- not equal Other relational operators are the same You may expand the relational statements by using the Logical Operators AND, OR The not logical operator is represented by !

5-7 If Construct Basic format if (expresson) { true statements } else { false statements } end if

5-8 If Examples if ($ans == “y”) or ($ans == “Y”) { echo (“We will continue”); } else { echo (“We are stopping”); } if ($total > 1.00) { $total += ($total * 0.07); }

5-9 More on If construct The else clause and false statements are optional The set of true or false statements are enclosed in braces Each if construct must end with the brace delimiter You may nest the if statements using the syntax if (condition) { true statement} elseif (condition) {true statement} else {false statements}

5-10 While Loop Checks the condition and if the condition is true the loop executes. The set of statements is enclosed in a set of brace Format While (expression) { statements }

5-11 While example $try_again = 5; while ($try_again > 0) { echo (“Take another guess” ) ; $try_again = $try_again – 1; }

5-12 For Loop Used when you know how many times you want the loop to execute. This loop structure assumes the loop counter will be incremented by 1 at the end of the loop. The statements for the loop are enclosed between the end of the count and the reserved word next

5-13 For Loop Format for (start counter; stop condition; change counter) {statements }

5-14 FOR Example dim $cntr; for ($cntr = 10; $cntr <= 20; $cntr++) { echo ($cntr); }