PHP练习--用for循环打印空心菱形 - jerrylsxu

思路：1，写出代码打印实心的金字塔

         2、修改代码，把金字塔抛空

　　　3、修改代码，把金字塔倒转

　　　4、修改倒转后的代码，把金字塔抛空

　　　5、修改代码，把具体的数进行参数化

1、写出代码打印实心金字的金字塔：

<span style="color: #000000;">php
    </span><span style="color: #008000;">//</span><span style="color: #008000;">$n=5;</span>
    <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$i</span>=1;<span style="color: #800080;">$i</span>$i++<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印空格</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$j</span>=1;<span style="color: #800080;">$j</span>$i;<span style="color: #800080;">$j</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
        }
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印*号</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$k</span>=1;<span style="color: #800080;">$k</span>$i-1;<span style="color: #800080;">$k</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
        }

        </span><span style="color: #0000ff;">echo</span> "<br>"<span style="color: #000000;">;
    }

</span>?>

 

2、

2、改善代码，把金字塔抛空

<span style="color: #000000;">php
    </span><span style="color: #008000;">//</span><span style="color: #008000;">$n=5;</span>
    <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$i</span>=1;<span style="color: #800080;">$i</span>$i++<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印空格</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$j</span>=1;<span style="color: #800080;">$j</span>$i;<span style="color: #800080;">$j</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
        }
    </span><span style="color: #008000;">//</span><span style="color: #008000;">打印*号</span>
    <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$k</span>=1;<span style="color: #800080;">$k</span>$i-1;<span style="color: #800080;">$k</span>++<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印第一行后最后一行都打*连接</span>
        <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$i</span>==1 || <span style="color: #800080;">$i</span>==5<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
        }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
        </span><span style="color: #008000;">//</span><span style="color: #008000;">怎么打空格和*号的问题</span>
            <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$k</span>==1 || <span style="color: #800080;">$k</span>==2*<span style="color: #800080;">$i</span>-1<span style="color: #000000;">){
                </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
            }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
            }
        }
    }
    </span><span style="color: #0000ff;">echo</span> "<br>"<span style="color: #000000;">;
    }

</span>?>

 

3、修改代码，把金字塔倒转

<span style="color: #000000;">php
    </span><span style="color: #008000;">//</span><span style="color: #008000;">$n=5;</span>
    <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$i</span>=1;<span style="color: #800080;">$i</span>$i++<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印空格</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$j</span>=1;<span style="color: #800080;">$j</span>$i;<span style="color: #800080;">$j</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
        }
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印*号</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$k</span>=1;<span style="color: #800080;">$k</span>$i-1;<span style="color: #800080;">$k</span>++<span style="color: #000000;">){
            </span><span style="color: #008000;">//</span><span style="color: #008000;">打印第一行后最后一行都打*连接</span>
            <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$i</span>==1 || <span style="color: #800080;">$i</span>==5<span style="color: #000000;">){
                    </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
            }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                </span><span style="color: #008000;">//</span><span style="color: #008000;">怎么打空格和*号的问题</span>
                <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$k</span>==1 || <span style="color: #800080;">$k</span>==2*<span style="color: #800080;">$i</span>-1<span style="color: #000000;">){
                    </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
                }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                    </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
                }
            }
        }
    </span><span style="color: #0000ff;">echo</span> "<br>"<span style="color: #000000;">;
    }
    </span><span style="color: #008000;">//</span><span style="color: #008000;">倒转</span>
    <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$i</span>=5;<span style="color: #800080;">$i</span>>=0;<span style="color: #800080;">$i</span>--<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印空格</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$j</span>=0;<span style="color: #800080;">$j</span>$i;<span style="color: #800080;">$j</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
        }
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印*号</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$k</span>=1;<span style="color: #800080;">$k</span>$i-3;<span style="color: #800080;">$k</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
        }
    </span><span style="color: #0000ff;">echo</span> "<br>"<span style="color: #000000;">;
    }
</span>?>

 

4、修改倒转后的代码，把金字塔抛空，并把中间的*号去掉 修改这里的代码（if($i==1 || $i==5){ //去掉$i==5 把中间抛空）

<span style="color: #000000;">php
    </span><span style="color: #008000;">//</span><span style="color: #008000;">$n=5;</span>
    <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$i</span>=1;<span style="color: #800080;">$i</span>$i++<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印空格</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$j</span>=1;<span style="color: #800080;">$j</span>$i;<span style="color: #800080;">$j</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
        }
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印*号</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$k</span>=1;<span style="color: #800080;">$k</span>$i-1;<span style="color: #800080;">$k</span>++<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印第一行后最后一行都打*连接($i==1 || $i==5) </span>
            <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$i</span>==1){ <span style="color: #008000;">//</span><span style="color: #008000;">去掉$i==5 把中间抛空</span>
                <span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
            }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                </span><span style="color: #008000;">//</span><span style="color: #008000;">怎么打空格和*号的问题</span>
                <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$k</span>==1 || <span style="color: #800080;">$k</span>==2*<span style="color: #800080;">$i</span>-1<span style="color: #000000;">){
                    </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
                }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                    </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
            }
        }
    }
    </span><span style="color: #0000ff;">echo</span> "<br>"<span style="color: #000000;">;
    }
    </span><span style="color: #008000;">//</span><span style="color: #008000;">倒转 抛空</span>
    <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$i</span>=5;<span style="color: #800080;">$i</span>>=0;<span style="color: #800080;">$i</span>--<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印空格</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$j</span>=0;<span style="color: #800080;">$j</span>$i;<span style="color: #800080;">$j</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
        }
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印*号</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$k</span>=1;<span style="color: #800080;">$k</span>$i-3;<span style="color: #800080;">$k</span>++<span style="color: #000000;">){
            </span><span style="color: #008000;">//</span><span style="color: #008000;">怎么打空格和*号的问题</span>
            <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$k</span>==2*<span style="color: #800080;">$i</span>-3 || <span style="color: #800080;">$k</span>==1<span style="color: #000000;">){
                </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
            }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;    
            }
        }
    </span><span style="color: #0000ff;">echo</span> "<br>"<span style="color: #000000;">;
    }
</span>?>

 

5、修改代码，把具体的数进行参数化 ：把具体数字5改成$n=5代替，随后可以设置$n的值，可以任意放大和缩小

<span style="color: #000000;">php
    </span><span style="color: #800080;">$n</span>=5<span style="color: #000000;">;
    </span><span style="color: #0000ff;">for</span>(<span style="color: #800080;">$i</span>=1;<span style="color: #800080;">$i</span>$n;<span style="color: #800080;">$i</span>++<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印空格</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$j</span>=1;<span style="color: #800080;">$j</span>$n-<span style="color: #800080;">$i</span>;<span style="color: #800080;">$j</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
        }
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印*号</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$k</span>=1;<span style="color: #800080;">$k</span>$i-1;<span style="color: #800080;">$k</span>++<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印第一行后最后一行都打*连接($i==1 || $i==5) </span>
            <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$i</span>==1){ <span style="color: #008000;">//</span><span style="color: #008000;">去掉$i==5 把中间抛空</span>
                <span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
            }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                </span><span style="color: #008000;">//</span><span style="color: #008000;">怎么打空格和*号的问题</span>
                <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$k</span>==1 || <span style="color: #800080;">$k</span>==2*<span style="color: #800080;">$i</span>-1<span style="color: #000000;">){
                    </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
                }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                    </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
                }
        }
    }
    </span><span style="color: #0000ff;">echo</span> "<br>"<span style="color: #000000;">;
    }
    </span><span style="color: #008000;">//</span><span style="color: #008000;">倒转 抛空</span>
    <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$i</span>=<span style="color: #800080;">$n</span>;<span style="color: #800080;">$i</span>>=0;<span style="color: #800080;">$i</span>--<span style="color: #000000;">){
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印空格</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$j</span>=0;<span style="color: #800080;">$j</span>$n-<span style="color: #800080;">$i</span>;<span style="color: #800080;">$j</span>++<span style="color: #000000;">){
            </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;
        }
        </span><span style="color: #008000;">//</span><span style="color: #008000;">打印*号</span>
        <span style="color: #0000ff;">for</span>(<span style="color: #800080;">$k</span>=1;<span style="color: #800080;">$k</span>$i-3;<span style="color: #800080;">$k</span>++<span style="color: #000000;">){
            </span><span style="color: #008000;">//</span><span style="color: #008000;">怎么打空格和*号的问题</span>
            <span style="color: #0000ff;">if</span>(<span style="color: #800080;">$k</span>==2*<span style="color: #800080;">$i</span>-3 || <span style="color: #800080;">$k</span>==1<span style="color: #000000;">){
                </span><span style="color: #0000ff;">echo</span> "*"<span style="color: #000000;">;
            }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
                </span><span style="color: #0000ff;">echo</span> " "<span style="color: #000000;">;    
            }
        }
    </span><span style="color: #0000ff;">echo</span> "<br>"<span style="color: #000000;">;
    }
</span>?>

 

效果图：

最后大功告成。顺便说说 ，其实编程不难，难就难在怎么样的思路，怎样去解决问题的方法。所以大家在编程的过程中善于思考。尽管花了半天的时间去想，但是最后想出来了，问题也得到解决，所以平时要多动脑动手去实践。我们的编程能力才能提高。只有实践了，东西才能被理解，知识点也掌握了。