switch的問題

[kuangxiang007]

我想寫一下的函數﹐但沒得到預期結果﹐我發現case后面的字串只有最后一個起作用﹐相信大家應該明白我的要求﹐請問怎樣能得到正確的結果﹐不要告訴我真的要每個字串就寫一個case哦

<script>
function getDbType(as_type){
switch(as_type.toLowerCase()){
case 'text','string':return 'string';break;
case 'number','int','i2','r4','float','i8','double':return 'number';break;
case 'date':return 'date';break;
case 'datetime':return 'datetime';break;
case 'boolean':return 'boolean';break;
}
return as_type.toLowerCase();
}
var a="r4"
alert(getDbType(a))//返回不了number
a="double"
alert(getDbType(a))//返回number
</script>

[ydr2002]

function getDbType(as_type){
var sType = "";
switch(as_type.toLowerCase()){
case "text":
case "string":
sType = "string";
break;
case "number":
case "int":
case "i2":
case "r4":
case "float":
case "i8":
case "double":
sType = "number";
break;
case "date":
sType = "date";
break;
case "datetime":
sType = "datetime";
break;
case "boolean":
sType = "boolean";
break;
default:
sType = as_type.toLowerCase();
break;
}
return sType;
}