var str = "a,b,c,d ";
var val = "123,34453,565467,564";
var arr=str.split(",");
var valarr=val.split(",");
for(i=0;i <=arr.length;i++){
eval( "var "+arr[i]+ "=\""+valarr[i]+ "\"; ");//需要注意的是,这里必须全部用eval括起来
}
alert(a+ " "+b+ " "+c+ " "+d);
eval不仅可以用在此处,还可以用在:后台传到页面上的字符串,转化为javascript代码的时候