输入只能是中文、英文和数字的正则表达式，怎么写最简便？

[mqcm001]

如题

[王集鹄]

/^[a-z\d][\u4e00-\u9fa5]$/i;

[王集鹄]

/^([a-z\d][\u4e00-\u9fa5])+$/i;

蹭分

[sohighthesky]

/^[a-z\d\u4e00-\u9fa5]*$/i;

[草根醉秋意]

var pattern = /^[a-zA-Z0-9\u4e00-\u9fa5]*$/;
alert(pattern.test("a2中文"));

噌分

[浴火_凤凰]

/^[a-zA-Z\d\u4e00-\u9fa5]+$/;