把KB转化为KB及以上单位

<span style="color: #008080;"> 1</span> <span style="color: #008000;">/*</span><span style="color: #008000;">*
</span><span style="color: #008080;"> 2</span> <span style="color: #008000;">*    把KB转化为KB及以上单位
</span><span style="color: #008080;"> 3</span> <span style="color: #008000;">*    @param int $kb
</span><span style="color: #008080;"> 4</span> <span style="color: #008000;">*    @return string $new_val
</span><span style="color: #008080;"> 5</span> <span style="color: #008000;">*/</span>
<span style="color: #008080;"> 6</span> <span style="color: #0000ff;">function</span> return_over_kb(<span style="color: #800080;">$kb</span><span style="color: #000000;">)
</span><span style="color: #008080;"> 7</span> <span style="color: #000000;">{
</span><span style="color: #008080;"> 8</span>     <span style="color: #800080;">$kb</span> /= 1024<span style="color: #000000;">;
</span><span style="color: #008080;"> 9</span>     <span style="color: #800080;">$unit</span> = 0; <span style="color: #008000;">//</span><span style="color: #008000;"> 0KB/MB 1GB 2TB 3PB 4EB</span>
<span style="color: #008080;">10</span>     <span style="color: #0000ff;">while</span> (<span style="color: #800080;">$kb</span> >= 1024<span style="color: #000000;">) {
</span><span style="color: #008080;">11</span>         <span style="color: #800080;">$kb</span> /= 1024<span style="color: #000000;">;
</span><span style="color: #008080;">12</span>         <span style="color: #800080;">$unit</span>++<span style="color: #000000;">;
</span><span style="color: #008080;">13</span> <span style="color: #000000;">    }
</span><span style="color: #008080;">14</span>     <span style="color: #0000ff;">switch</span> (<span style="color: #800080;">$unit</span><span style="color: #000000;">) {
</span><span style="color: #008080;">15</span>         <span style="color: #0000ff;">case</span> 1: <span style="color: #800080;">$b</span> = 'GB'; <span style="color: #0000ff;">break</span><span style="color: #000000;">;
</span><span style="color: #008080;">16</span>         <span style="color: #0000ff;">case</span> 2: <span style="color: #800080;">$b</span> = 'TB'; <span style="color: #0000ff;">break</span><span style="color: #000000;">;
</span><span style="color: #008080;">17</span>         <span style="color: #0000ff;">case</span> 3: <span style="color: #800080;">$b</span> = 'PB'; <span style="color: #0000ff;">break</span><span style="color: #000000;">;
</span><span style="color: #008080;">18</span>         <span style="color: #0000ff;">case</span> 4: <span style="color: #800080;">$b</span> = 'EB'; <span style="color: #0000ff;">break</span><span style="color: #000000;">;
</span><span style="color: #008080;">19</span>         <span style="color: #0000ff;">default</span>: 
<span style="color: #008080;">20</span>             <span style="color: #0000ff;">if</span> (<span style="color: #800080;">$kb</span> >= 1<span style="color: #000000;">) {
</span><span style="color: #008080;">21</span>                 <span style="color: #800080;">$b</span> = 'MB'<span style="color: #000000;">;
</span><span style="color: #008080;">22</span>             } <span style="color: #0000ff;">else</span><span style="color: #000000;"> {
</span><span style="color: #008080;">23</span>                 <span style="color: #800080;">$b</span> = 'KB'<span style="color: #000000;">;
</span><span style="color: #008080;">24</span> <span style="color: #000000;">            }
</span><span style="color: #008080;">25</span>         <span style="color: #0000ff;">break</span><span style="color: #000000;">;
</span><span style="color: #008080;">26</span> <span style="color: #000000;">    }
</span><span style="color: #008080;">27</span> 
<span style="color: #008080;">28</span>     <span style="color: #0000ff;">if</span> (<span style="color: #800080;">$unit</span> == 0) { <span style="color: #008000;">//</span><span style="color: #008000;"> 要么是KB 要么是MB</span>
<span style="color: #008080;">29</span>         <span style="color: #0000ff;">if</span> (<span style="color: #800080;">$kb</span> ) {
<span style="color: #008080;">30</span>             <span style="color: #800080;">$kb</span> *= 1024<span style="color: #000000;">;
</span><span style="color: #008080;">31</span> <span style="color: #000000;">        }
</span><span style="color: #008080;">32</span> <span style="color: #000000;">    }
</span><span style="color: #008080;">33</span> 
<span style="color: #008080;">34</span>     <span style="color: #0000ff;">return</span> <span style="color: #008080;">round</span>(<span style="color: #800080;">$kb</span>, 1) . <span style="color: #800080;">$b</span><span style="color: #000000;">;
</span><span style="color: #008080;">35</span> }