var = ["弱","中","强","超强"];
function checkStrong(val) {
var modes = 0;
if (val.length < 6) return 0;
if (/\d/.test(val)) modes++; //数字
if (/[a-z]/.test(val)) modes++; //小写
if (/[A-Z]/.test(val)) modes++; //大写
if (/\W/.test(val)) modes++; //特殊字符
if (val.length > 12) return 4;
return modes;
}