PHP kezdőknek és haladóknak

PHP beépített abs függvény használata

pl:
<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Listing 6.1 Calling the Built-in abs() function</title>
</head>
<body>
<div>
<?php
$num = -321;
$newnum = abs( $num );
print $newnum;
// prints "321"
?>
</div>
</body>
</html>
Eredmény:

321

HTML használata 1 kód-blokk belsejében

Vagyis a PHP vége, kezdete jelzés közé írhatunk HTML kódot.
pl:
<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Listing 5.14 Returning to HTML Mode Within a Code Block</title>
</head>
<body>
<div>
<?php
$display_prices = true;

if ( $display_prices ) {
?>
    <table border="1">
    <tr><td colspan="3">todays prices in dollars</td></tr><tr>
    <td>14</td><td>32</td><td>71</td>
    </tr></table>
<?php
}

?>
</div>
</body>
</html>
Eredmény:

todays prices in dollars
14	32	71

Egy kód-blokk tartalmazhat több kiírást - formázáshoz

pl:
<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Listing 5.13 A Code Block Containing Multiple print() statements</title>
</head>
<body>
<div>
<?php
$display_prices = true;

if ( $display_prices ) {
    print "<table border=\"1\">";
    print "<tr><td colspan=\"3\">";
    print "todays prices in dollars";
    print "</td></tr><tr>";
    print "<td>14</td><td>32</td><td>71</td>";
    print "</tr></table>";
}

?>
</div>
</body>
</html>
Eredmény:

todays prices in dollars
14	32	71

Egymásba ágyazott ciklusok

A külső ciklus minden számlálása között lefut 1 teljes belső ciklus.
Pl:
<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Listing 5.12 Nesting Two for Loops</title>
</head>
<body>
<div>
<?php
print "<table border=\"0\">\n";
for ( $y=1; $y<=12; $y++ ) {
    print "<tr>\n";
    for ( $x=1; $x<=12; $x++ ) {
        print "\t<td>";
        print ($x*$y);
        print "</td>\n";
    }
    print "</tr>\n";
}
print "</table>";
?>
</div>
</body>
</html>
Eredmény:

1	2	3	4	5	6	7	8	9	10	11	12
2	4	6	8	10	12	14	16	18	20	22	24
3	6	9	12	15	18	21	24	27	30	33	36
4	8	12	16	20	24	28	32	36	40	44	48
5	10	15	20	25	30	35	40	45	50	55	60
6	12	18	24	30	36	42	48	54	60	66	72
7	14	21	28	35	42	49	56	63	70	77	84
8	16	24	32	40	48	56	64	72	80	88	96
9	18	27	36	45	54	63	72	81	90	99	108
10	20	30	40	50	60	70	80	90	100	110	120
11	22	33	44	55	66	77	88	99	110	121	132
12	24	36	48	60	72	84	96	108	120	132	144

continue: folytatás a következő ciklustól

pl:
<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Listing 5.11 Using the continue Statement</title>
</head>
<body>
<div>
<?php
$counter = -4;
for ( ; $counter <= 10; $counter++ ) {
    if ( $counter == 0 ) {
        continue;
    }
    $temp = 4000/$counter;
    print "4000 divided by $counter is... $temp<br />";
}
?>
</div>
</body>
</html>
Eredmény:

4000 divided by -4 is... -1000
4000 divided by -3 is... -1333.3333333333
4000 divided by -2 is... -2000
4000 divided by -1 is... -4000
4000 divided by 1 is... 4000
4000 divided by 2 is... 2000
4000 divided by 3 is... 1333.3333333333
4000 divided by 4 is... 1000
4000 divided by 5 is... 800
4000 divided by 6 is... 666.66666666667
4000 divided by 7 is... 571.42857142857
4000 divided by 8 is... 500
4000 divided by 9 is... 444.44444444444
4000 divided by 10 is... 400

break: kiugrás a ciklusból

pl:
<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Listing 5.10 Using the break Statement</title>
</head>
<body>
<div>
<?php
$counter = -4;
for ( ; $counter <= 10; $counter++ ) {
    if ( $counter == 0 ) {
        break;
    }
    $temp = 4000/$counter;
    print "4000 divided by $counter is... $temp<br />";
}
?>
</div>
</body>
</html>
Eredmény:

4000 divided by -4 is... -1000
4000 divided by -3 is... -1333.3333333333
4000 divided by -2 is... -2000
4000 divided by -1 is... -4000

A for ciklus

Formája:
for ( kezdőérték; feltétel; számolási parancs) {
   }

pl:
<!DOCTYPE html PUBLIC
    "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Listing 5.8 Using the for Statement</title>
</head>
<body>
<div>
<?php
for ( $counter=1; $counter<=12; $counter++ ) {
    print "$counter times 2 is ".($counter*2)."<br />";
}
?>
</div>
</body>
</html>
Eredmény:

1 times 2 is 2
2 times 2 is 4
3 times 2 is 6
4 times 2 is 8
5 times 2 is 10
6 times 2 is 12
7 times 2 is 14
8 times 2 is 16
9 times 2 is 18
10 times 2 is 20
11 times 2 is 22
12 times 2 is 24

1	2	3	4	5	6	7	8	9	10	11	12
2	4	6	8	10	12	14	16	18	20	22	24
3	6	9	12	15	18	21	24	27	30	33	36
4	8	12	16	20	24	28	32	36	40	44	48
5	10	15	20	25	30	35	40	45	50	55	60
6	12	18	24	30	36	42	48	54	60	66	72
7	14	21	28	35	42	49	56	63	70	77	84
8	16	24	32	40	48	56	64	72	80	88	96
9	18	27	36	45	54	63	72	81	90	99	108
10	20	30	40	50	60	70	80	90	100	110	120
11	22	33	44	55	66	77	88	99	110	121	132
12	24	36	48	60	72	84	96	108	120	132	144

1	2	3	4	5	6	7	8	9	10	11	12
2	4	6	8	10	12	14	16	18	20	22	24
3	6	9	12	15	18	21	24	27	30	33	36
4	8	12	16	20	24	28	32	36	40	44	48
5	10	15	20	25	30	35	40	45	50	55	60
6	12	18	24	30	36	42	48	54	60	66	72
7	14	21	28	35	42	49	56	63	70	77	84
8	16	24	32	40	48	56	64	72	80	88	96
9	18	27	36	45	54	63	72	81	90	99	108
10	20	30	40	50	60	70	80	90	100	110	120
11	22	33	44	55	66	77	88	99	110	121	132
12	24	36	48	60	72	84	96	108	120	132	144

2014. szeptember 11., csütörtök

1	2	3	4	5	6	7	8	9	10	11	12
2	4	6	8	10	12	14	16	18	20	22	24
3	6	9	12	15	18	21	24	27	30	33	36
4	8	12	16	20	24	28	32	36	40	44	48
5	10	15	20	25	30	35	40	45	50	55	60
6	12	18	24	30	36	42	48	54	60	66	72
7	14	21	28	35	42	49	56	63	70	77	84
8	16	24	32	40	48	56	64	72	80	88	96
9	18	27	36	45	54	63	72	81	90	99	108
10	20	30	40	50	60	70	80	90	100	110	120
11	22	33	44	55	66	77	88	99	110	121	132
12	24	36	48	60	72	84	96	108	120	132	144