This article uses object-oriented technology to implement a simple graphic area calculator
<span style="color: #008000;">//</span><span style="color: #008000;">rect.class.php</span> <?<span style="color: #000000;">php </span><span style="color: #0000ff;">abstract</span> <span style="color: #0000ff;">class</span><span style="color: #000000;"> Shape{ </span><span style="color: #0000ff;">public</span> <span style="color: #800080;">$name</span><span style="color: #000000;">; </span><span style="color: #0000ff;">abstract</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> area(); </span><span style="color: #0000ff;">abstract</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> view(); </span><span style="color: #0000ff;">abstract</span> <span style="color: #0000ff;">function</span> test(<span style="color: #800080;">$arr</span><span style="color: #000000;">); } </span>?>
<span style="color: #008000;">//</span><span style="color: #008000;">index.php</span> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> <style> .<span style="color: #000000;">box{ width</span>:<span style="color: #000000;"> 800px; margin</span>: 0<span style="color: #000000;"> auto; } </span></style> </head> <body> <div <span style="color: #0000ff;">class</span>="box"> <h1>图形计算器</h1> <div> <a href="index.php?action=rect">矩形</a> <a href="index.php?action=triangle">三角形</a> </div> </div> <?<span style="color: #000000;">php </span><span style="color: #008080;">error_reporting</span>(<span style="color: #ff00ff;">E_ALL</span> & ~<span style="color: #ff00ff;">E_NOTICE</span><span style="color: #000000;">); </span><span style="color: #0000ff;">function</span> __autoload(<span style="color: #800080;">$classname</span><span style="color: #000000;">){ </span><span style="color: #0000ff;">include</span> <span style="color: #008080;">strtolower</span>(<span style="color: #800080;">$classname</span>).".class.php"<span style="color: #000000;">; } </span><span style="color: #0000ff;">if</span>(!<span style="color: #0000ff;">empty</span>(<span style="color: #800080;">$_GET</span>['action'<span style="color: #000000;">])) { </span><span style="color: #800080;">$classname</span> = <span style="color: #008080;">ucfirst</span>(<span style="color: #800080;">$_GET</span>['action'<span style="color: #000000;">]); </span><span style="color: #800080;">$shape</span>=<span style="color: #0000ff;">new</span> <span style="color: #800080;">$classname</span>(<span style="color: #800080;">$_POST</span><span style="color: #000000;">); </span><span style="color: #800080;">$shape</span>-><span style="color: #000000;">view(); </span><span style="color: #0000ff;">if</span>(<span style="color: #0000ff;">isset</span>(<span style="color: #800080;">$_POST</span>['dosubmit'<span style="color: #000000;">])) { </span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$shape</span>->test(<span style="color: #800080;">$_POST</span><span style="color: #000000;">)) { </span><span style="color: #0000ff;">echo</span> <span style="color: #800080;">$shape</span>->name."的面积为:".<span style="color: #800080;">$shape</span>->area()."<br>"<span style="color: #000000;">; } } }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{ </span><span style="color: #0000ff;">echo</span> "请选择一个要计算的图形!<br>"<span style="color: #000000;">; } </span>?> </body> </html>
<span style="color: #008000;">//</span><span style="color: #008000;">rect.class.php</span> <?<span style="color: #000000;">php </span><span style="color: #0000ff;">class</span> Rect <span style="color: #0000ff;">extends</span><span style="color: #000000;"> Shape{ </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$width</span><span style="color: #000000;">; </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$height</span><span style="color: #000000;">; </span><span style="color: #0000ff;">function</span> __construct(<span style="color: #800080;">$arr</span>=<span style="color: #000000;">[]){ </span><span style="color: #0000ff;">if</span>(!<span style="color: #0000ff;">empty</span>(<span style="color: #800080;">$arr</span><span style="color: #000000;">)){ </span><span style="color: #800080;">$this</span>->width = <span style="color: #800080;">$arr</span>['width'<span style="color: #000000;">]; </span><span style="color: #800080;">$this</span>->height = <span style="color: #800080;">$arr</span>['height'<span style="color: #000000;">]; } </span><span style="color: #800080;">$this</span>->name = "矩形"<span style="color: #000000;">; } </span><span style="color: #0000ff;">function</span><span style="color: #000000;"> area() { </span><span style="color: #0000ff;">return</span> <span style="color: #800080;">$this</span>->width * <span style="color: #800080;">$this</span>-><span style="color: #000000;">height; } </span><span style="color: #0000ff;">function</span><span style="color: #000000;"> view() { </span><span style="color: #800080;">$form</span> = '<form action="index.php?action=rect" method="post">'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .=<span style="color: #800080;">$this</span>->name.'的宽:<input name="width" value=""/><br>'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .=<span style="color: #800080;">$this</span>->name.'的高:<input name="height" value=""/><br>'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .='<input type="submit" name="dosubmit" value="计算"><br>'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .='</form>'<span style="color: #000000;">; </span><span style="color: #0000ff;">echo</span> <span style="color: #800080;">$form</span><span style="color: #000000;">; } </span><span style="color: #0000ff;">function</span> test(<span style="color: #800080;">$arr</span><span style="color: #000000;">) { </span><span style="color: #800080;">$bg</span> = <span style="color: #0000ff;">true</span><span style="color: #000000;">; </span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$arr</span>['width'] < 0<span style="color: #000000;">) { </span><span style="color: #0000ff;">echo</span> <span style="color: #800080;">$this</span>->name."的宽不能小于0!<br>"<span style="color: #000000;">; </span><span style="color: #800080;">$bg</span> = <span style="color: #0000ff;">false</span><span style="color: #000000;">; } </span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$arr</span>['height'] < 0<span style="color: #000000;">) { </span><span style="color: #0000ff;">echo</span> <span style="color: #800080;">$this</span>->name."的高度不能小于0!<br>"<span style="color: #000000;">; </span><span style="color: #800080;">$bg</span> = <span style="color: #0000ff;">false</span><span style="color: #000000;">; } </span><span style="color: #0000ff;">return</span> <span style="color: #800080;">$bg</span><span style="color: #000000;">; } } </span>?>
<span style="color: #008000;">//</span><span style="color: #008000;">triangle.class.php</span> <?<span style="color: #000000;">php </span><span style="color: #0000ff;">class</span> Triangle <span style="color: #0000ff;">extends</span><span style="color: #000000;"> Shape{ </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$b1</span><span style="color: #000000;">; </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$b2</span><span style="color: #000000;">; </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$b3</span><span style="color: #000000;">; </span><span style="color: #0000ff;">function</span> __construct(<span style="color: #800080;">$arr</span>=<span style="color: #000000;">[]){ </span><span style="color: #0000ff;">if</span>(!<span style="color: #0000ff;">empty</span>(<span style="color: #800080;">$arr</span><span style="color: #000000;">)){ </span><span style="color: #800080;">$this</span>->b1 = <span style="color: #800080;">$arr</span>['b1'<span style="color: #000000;">]; </span><span style="color: #800080;">$this</span>->b2 = <span style="color: #800080;">$arr</span>['b2'<span style="color: #000000;">]; </span><span style="color: #800080;">$this</span>->b3 = <span style="color: #800080;">$arr</span>['b3'<span style="color: #000000;">]; } </span><span style="color: #800080;">$this</span>->name = "三角形"<span style="color: #000000;">; } </span><span style="color: #0000ff;">function</span><span style="color: #000000;"> area() { </span><span style="color: #800080;">$p</span> = (<span style="color: #800080;">$this</span>->b1 + <span style="color: #800080;">$this</span>->b2 + <span style="color: #800080;">$this</span>->b3)/2<span style="color: #000000;">; </span><span style="color: #0000ff;">return</span> <span style="color: #008080;">sqrt</span>(<span style="color: #800080;">$p</span>*(<span style="color: #800080;">$p</span>-<span style="color: #800080;">$this</span>->b1)*(<span style="color: #800080;">$p</span>-<span style="color: #800080;">$this</span>->b2)*(<span style="color: #800080;">$p</span>-<span style="color: #800080;">$this</span>-><span style="color: #000000;">b3)); } </span><span style="color: #0000ff;">function</span><span style="color: #000000;"> view() { </span><span style="color: #800080;">$form</span> = '<form action="index.php?action=triangle" method="post">'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .=<span style="color: #800080;">$this</span>->name.'第一个边的宽:<input name="b1" value=""/><br>'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .=<span style="color: #800080;">$this</span>->name.'第二个边的宽:<input name="b2" value=""/><br>'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .=<span style="color: #800080;">$this</span>->name.'第三个边的宽:<input name="b3" value=""/><br>'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .='<input type="submit" name="dosubmit" value="计算"><br>'<span style="color: #000000;">; </span><span style="color: #800080;">$form</span> .='</form>'<span style="color: #000000;">; </span><span style="color: #0000ff;">echo</span> <span style="color: #800080;">$form</span><span style="color: #000000;">; } </span><span style="color: #0000ff;">function</span> test(<span style="color: #800080;">$arr</span><span style="color: #000000;">) { </span><span style="color: #800080;">$bg</span> = <span style="color: #0000ff;">true</span><span style="color: #000000;">; </span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$arr</span>['b1'] < 0<span style="color: #000000;">) { </span><span style="color: #0000ff;">echo</span> "第一个边的宽不能小于0!<br>"<span style="color: #000000;">; </span><span style="color: #800080;">$bg</span> = <span style="color: #0000ff;">false</span><span style="color: #000000;">; } </span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$arr</span>['b2'] < 0<span style="color: #000000;">) { </span><span style="color: #0000ff;">echo</span> "第二个边的宽不能小于0!<br>"<span style="color: #000000;">; </span><span style="color: #800080;">$bg</span> = <span style="color: #0000ff;">false</span><span style="color: #000000;">; } </span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$arr</span>['b3'] < 0<span style="color: #000000;">) { </span><span style="color: #0000ff;">echo</span> "第三个边的宽不能小于0!<br>"<span style="color: #000000;">; </span><span style="color: #800080;">$bg</span> = <span style="color: #0000ff;">false</span><span style="color: #000000;">; } </span><span style="color: #0000ff;">if</span>((<span style="color: #800080;">$arr</span>['b1'] + <span style="color: #800080;">$arr</span>['b2'] < <span style="color: #800080;">$arr</span>['b3'])||(<span style="color: #800080;">$arr</span>['b1'] + <span style="color: #800080;">$arr</span>['b3'] < <span style="color: #800080;">$arr</span>['b2'])||(<span style="color: #800080;">$arr</span>['b3'] + <span style="color: #800080;">$arr</span>['b2'] < <span style="color: #800080;">$arr</span>['b1'<span style="color: #000000;">])){ </span><span style="color: #0000ff;">echo</span> '两边之和不能小于第三边<br>'<span style="color: #000000;">; </span><span style="color: #800080;">$bg</span> = <span style="color: #0000ff;">false</span><span style="color: #000000;">; } </span><span style="color: #0000ff;">return</span> <span style="color: #800080;">$bg</span><span style="color: #000000;">; } } </span>?>