前端学PHP之面向对象系列第六篇简单图形面积计算器实现

<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>



<meta charset="UTF-8"><title>Document</title><style>
.<span style="color: #000000;">box{
    width:<span style="color: #000000;"> 800px;
    margin: 0<span style="color: #000000;"> auto;
}
</style><div style="color: #0000ff;">class="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>?>

<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> = '

'; $form .=$this->name.'的宽:
'; $form .=$this->name.'的高:
'; $form .='
'; $form .='

'; echo $form; } function test($arr) { $bg = true; if($arr['width'] ) { echo $this->name."的宽不能小于0!
"; $bg = false; } if($arr['height'] ) { echo $this->name."的高度不能小于0!
"; $bg = false; } return $bg; } } ?>

<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> = '

'; $form .=$this->name.'第一个边的宽:
'; $form .=$this->name.'第二个边的宽:
'; $form .=$this->name.'第三个边的宽:
'; $form .='
'; $form .='

'; echo $form; } function test($arr) { $bg = true; if($arr['b1'] ) { echo "第一个边的宽不能小于0!
"; $bg = false; } if($arr['b2'] ) { echo "第二个边的宽不能小于0!
"; $bg = false; } if($arr['b3'] ) { echo "第三个边的宽不能小于0!
"; $bg = false; } if(($arr['b1'] + $arr['b2'] $arr['b3'])||($arr['b1'] + $arr['b3'] $arr['b2'])||($arr['b3'] + $arr['b2'] $arr['b1'])){ echo '两边之和不能小于第三边
'; $bg = false; } return $bg; } } ?>