js遍历二维数组

 1 //求平均数
 2 var pjs=[
 3         [‘小明‘,87],
 4         [‘小红‘,81],
 5         [‘小花‘,97],
 6         [‘小天‘,76],
 7         [‘小张‘,74],
 8         [‘小小‘,94],
 9         [‘小西‘,90],
10         [‘小武‘,76],
11         [‘小迪‘,64],
12         [‘小曼‘,76]
13 ]
14 var i,j;
15 var sum=0;
16 for(var i=0;i<pjs.length;i++){
17 
18   for(j=0;j<pjs[i].length;j++)
19   {
20       if(j==pjs[i].length-1)
21       {
22           sum+=pjs[i][j];
23           
24       }
25       
26   }
27 }
28 sum=sum/pjs.length
29 document.write(sum+"<br />");