js数组合并

    // 第一种  
    var mergeTo = [4,5,6],  
          mergeFrom = [7,8,9];  
      
    mergeTo = mergeTo.concat(mergeFrom);  
    mergeTo; // is: [4, 5, 6, 7, 8, 9]  
      
    or  
    var a = [1,2], b = [3,4], c = a.concat(b);  
      
      
    // 第二种  
    var mergeTo = [4,5,6],  
    var mergeFrom = [7,8,9];  
      
    Array.prototype.push.apply(mergeTo, mergeFrom);  
      
    mergeTo; // is: [4, 5, 6, 7, 8, 9]