в 10:37, 26 мая 2010

2010-05-26T10:37:28Z

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2010-05-26T07:06:44Z

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==Greate and equal==



<source lang="html4strict">

<?
$a = 21;
$b = 15;
echo "Original value of \$a is $a and \$b is $b";
if ($a >= $b) {
echo "TEST\$a is greater than or equal to \$b";
} else {
echo "TEST\$a is not greater than or equal to \$b";
}
?>

</source>

==Greater than==



<source lang="html4strict">

<?
$a = 21;
$b = 15;
echo "Original value of \$a is $a and \$b is $b";
if ($a > $b) {
echo "TEST \$a is greater than \$b";
} else {
echo "TEST \$a is not greater than \$b";
}
?>

</source>

==Leap Year Determination==



<source lang="html4strict">

<?php
function is_leap_year($year) {
return ((($y % 4) == 0) && ((($y % 100) != 0) || (($y % 400) == 0)));
}
foreach (range(1999, 2009) as $year) {
echo "{$year} = ", is_leap_year($year) ? "Leap Year" : "not", "";
}
?>

</source>

==Less than==



<source lang="html4strict">

<?
$a = 21;
$b = 15;
echo "Original value of \$a is $a and \$b is $b";
if ($a < $b) {
echo "TEST\$a is less than \$b";
} else {
echo "TEST\$a is not less than \$b";
}
?>

</source>

==Less than and equal==



<source lang="html4strict">

<?
$a = 21;
$b = 15;
echo "Original value of \$a is $a and \$b is $b";
if ($a <= $b) {
echo "TEST\$a is less than or equal to \$b";
} else {
echo "TEST\$a is not less than or equal to \$b";
}
?>

</source>

==Logical Operators==



<source lang="html4strict">

Operator Name Returns True if... Example Result

|| Or Left or right is true true || false true

or Or Left or right is true true || false true

xor Xor Left or right is true but not both true xor true false

&& And Left and right are true true && false false

and And Left and right are true true && false false

! Not The single operand is not true ! true false

<?php
$a = true; $b = false;
#test both operands for true
$test1 = ( $a and $a )? "true":"false";
$test2 = ( $a and $b )? "true":"false";
$test3 = ( $b and $b )? "true":"false";
#test either operand for true
$test4 = ( $a or $a )? "true":"false";
$test5 = ( $a or $b )? "true":"false";
$test6 = ( $b or $b )? "true":"false";
#test for single operand is true
$test7 = ( $a xor $a )? "true":"false";
$test8 = ( $a xor $b )? "true":"false";
$test9 = ( $b xor $b )? "true":"false";
#invert values
$test10 = ( !$a )? "true":"false";
$test11 = ( !$b )? "true":"false";
$result = "AND - 1:$test1 2:$test2 3:$test3 ";
$result .= "OR   - 1:$test4 2:$test5 3:$test6 ";
$result .= "XOR - 1:$test7 2:$test8 3:$test9 ";
$result .= "NOT - 1:$test10 2:$test11";

echo( $result );
?>

<?
$age = 20;
if (($age >= 13) && ($age < 65)) {
print "too old for a kid"s discount and too young for the senior"s discount.";
}
$meal = "breakfast";
if (($meal == "breakfast") || ($dessert == "souffle")) {
print "Time to eat some eggs.";
}
?>

</source>

==Logical Operators in Order of Precedence==



<source lang="html4strict">



</source>

==Logic Operators in PHP==



<source lang="html4strict">

Operator Action

$foo and $bar TRue if $foo and $bar are TRue

$foo or $bar true if $foo or $bar is true

$foo xor $bar true if and only if $foo or $bar is true (only one or the other)

!$foo true if $foo is not true

$foo && $bar TRue if $foo and $bar are true

$foo || $bar true if $foo or $bar is true

</source>

==Negation operator==



<source lang="html4strict">

$first_name = "first";
$last_name = "last";
<?
if (! strcasecmp($first_name,$last_name)) {
print "$first_name and $last_name are equal.";
}
?>

</source>

==Not equal: !===



<source lang="html4strict">

<?
$a = 21;
$b = 15;
echo "Original value of \$a is $a and \$b is $b";

if ($a != $b) {
echo "TEST\$a is not equal to \$b";
} else {
echo "TEST\$a is equal to \$b";
}
?>

</source>

==Or operator==



<source lang="html4strict">

<?php
$user1 = "Paul";
$user2 = "Donna";
if ($username == $user1 || $username == $user2)
{
print "$username welcome.";
}
?>

</source>

==Relational Operators in action==



<source lang="html4strict">
<html>
<head>
<title>Relational Operators</title>
</head>
<body>
<?php
print("(5 < 5) is " . ((5 < 5) ? "True" : "False") . " ");
print("(5 <= 5) is " . ((5 <= 5) ? "True" : "False") . " ");
print("(5 > 5) is " . ((5 > 5) ? "True" : "False") . " ");
print("(5 >= 5) is " . ((5 >= 5) ? "True" : "False") . " ");
?>
</body>
</html>

</source>

==Relational Operators summary table==



<source lang="html4strict">


</source>

==The not-equals operator==



<source lang="html4strict">

<?
$new_messages = 10

if ($new_messages != 10) {
print "You don"t have ten new messages.";
}
if ($dinner != "B") {
print "not b";
}
?>

</source>

==Use the boolean compare operators==



<source lang="html4strict">

<?
$three = 3;
$four = 4;
$my_pi = 3.14159;
if (($three == $three) and
($four === $four) and
($three != $four) and
($three < $four) and
($three <= $four) and
($four >= $three) and
($three <= $three) and
($my_pi > $three) and
($my_pi <= $four))
print("Yes! ");
else
print("No? ");
?>

</source>

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в 10:37, 26 мая 2010

Admin: 1 версия