javascript实现九九乘法表

左下角

 1 function leftdown(){
 2         document.write("<table>");
 3         for(var i=1;i<=9;i++)
 4             {   
 5                  document.writeln("<tr>");
 6 
 7                 for(var j=1;j<=i;j++)
 8                 {
 9                     var m=i*j;
10                     document.write("<td>"+j+"*"+i+"="+m+"</td>");
11                 }document.write("</tr>");
12             }
13             document.write("</table>");
14 
15     }
16 
17     leftdown();
18     document.write("</br>");

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左上角

 1 function lefttop(){
 2         document.writeln("<table>");
 3         for(var i=1;i<=9;i++)
 4             {document.writeln("<tr>");
 5                 for(var j=i;j<=9;j++)
 6                 {
 7                     var m=i*j;
 8                     document.write("<td>"+i+"*"+j+"="+m+"</td> ");
 9                 }document.write("</tr>");
10             }document.write("</table>");
11 
12     }
13     lefttop();
14     document.write("</br>");

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右下角

 1 function rightdown(){
 2                 document.write("<table>");
 3                 for(var i=1;i<=9;i++)
 4 
 5                         {
 6                                 document.writeln("<tr>");
 7                                 for(var k=1;k<=9-i;k++)
 8                                         {
 9                                                 document.write("<td style='border:none'></td>");
10 
11                                         }
12                                 for(var j=1;j<=9;j++)
13                                 {
14                                         if(j>i){
15                                                 document.write(" ");
16                                         }
17                                         else{
18                                                 var m=i*j;
19                                         document.write("<td>"+i+"*"+j+"="+m+"</td>");
20 
21                                         }
22 
23                                 }document.writeln("</tr>");
24                                 
25                         }document.writeln("</table>");
26 
27         }
28         rightdown();
29         document.write("</br>");

View Code

右上角

 1 function righttop(){
 2         document.write("<table>");
 3         for(var i=1;i<=9;i++)
 4             {
 5                 document.writeln("<tr>");
 6                 for(var j=1;j<=9;j++)
 7                 {
 8                     
 9                     if(i>j){
10                         document.write("<td style='border:none'></td>");
11                     }
12                     else{
13                     var m=i*j;
14                     document.write("<td>"+i+"*"+j+"="+m+"</td>");
15 
16                     }
17         
18                 }document.writeln("</tr>");
19                 
20             }document.writeln("</table>");
21 
22     }
23     righttop();
24     document.write("</br>");

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