計算機、例：１
keisan.php
<?php
function keisan( ) {
$n1 = $_POST[ 'n1' ];
$n2 = $_POST[ 'n2' ];
$keisan = $_POST[ 'keisan' ];
if( empty( $n1 ) || empty( $n2 ) ) {
$error = '入力されてないよ！';
} else if( !is_numeric( $n1 ) || !is_numeric( $n2 ) ) {
$error = '数字じゃないよ！';
}
if ( isset( $error ) ) {
echo $error;
} else {
switch ( $keisan ) {
case 'plus':
echo $n1 + $n2;
break;
case 'minus':
echo $n1 - $n2;
break;
case 'bi':
echo $n1 * $n2;
break;
case 'divide':
echo $n1 / $n2;
break;
}
}
}
?>
計算機、例：２
keisan.php
<?php
require_once dirname(__FILE__).'/kansu.php';
?>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<form method="POST" action="<?php $_SERVER[ 'PHP_SELF' ]; ?>">
<input type="text" name="n1">
<select name="keisan">
<option value="plus">+</option>
<option value="minus">-</option>
<option value="bi">*</option>
<option value="divide">/</option>
</select>
<input type="text" name="n2">
<input type="hidden" name="_submit_check" value="1">
<input type="submit" value="計算！"><br>
</form>
<?php
if( isset( $_POST[ '_submit_check' ] ) ) {
keisan( );
}
?>
</body>
</html>
kansu.php
<?php
function keisan( ) {
$n1 = $_POST[ 'n1' ];
$n2 = $_POST[ 'n2' ];
$keisan = $_POST[ 'keisan' ];
if( ( empty( $n1 )) || ( empty( $n2 ) )) {
$error = '入力されてないよ！';
} else if( ( !is_numeric( $n1 ) ) || ( !is_numeric( $n2 ) ) ) {
$error = '数字じゃないよ！';
}
if ( isset( $error ) ) {
echo $error;
} else {
switch ( $keisan ) {
case 'plus':
echo $n1 + $n2;
break;
case 'minus':
echo $n1 - $n2;
break;
case 'bi':
echo $n1 * $n2;
break;
case 'divide':
echo $n1 / $n2;
break;
}
}
}
?>
3の倍数と3の付く数字の時だけ違う処理、例：１
aho.php
<?php
$number = 1;
while ( $number <= 40 ) {
if ( $number % 3 == 0 || preg_match( '/3/', strval( $number ) ) ) {
echo 'Aho ';
} else {
echo $number . ' ';
}
$number++;
}
?>
3の倍数と3の付く数字の時だけ違う処理、例：２
aho.php
<!doctype html>
<html lang="ja">
<head>
<meta charset="UTF-8">
<title>3の倍数</title>
</head>
<body>
<?php
for( $i = 1; $i <= 40; $i++ ){
if( $i % 3 === 0 || strstr( $i, '3' ) ){
echo 'Aho';
}else{
echo $i;
}
}
?>
</body>
</html>
ページ遷移しないフォーム、例：１
hello.php
<?php
if( isset( $_POST[ 'submit' ] ) ) {
echo 'こんにちは、' . htmlspecialchars( $_POST[ 'name' ] ) . 'さん！';
} else {
echo<<<_HTML_
<!doctype html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<form method="POST" action="{$_SERVER[ 'PHP_SELF' ]}">
<h1>名前を入力してください。</h1>
<input type="text" name="name" placeholder="いとうようへい">
<input type="submit" name="submit">
</form>
</body>
</html>
_HTML_;
}
?>
ページ遷移しないフォーム、例：２
hello.php
<!doctype html>
<html lang="ja">
<head>
<meta charset="UTF-8">
<title>送信</title>
</head>
<body>
<?php
if( !isset( $_POST[ 'name' ] ) ){
$a=<<<EOM
<h1>名前を入力してください。</h1>
<form method="post" action=" ">
<input type="text" name="name" placeholder="いとうようへい">
<input type="submit" value="送信">
</form>
EOM;
echo $a;
}else{
echo $_POST[ 'name' ];
}
?>
</body>
</html>
