Regular Expression to verify string Composition

Regular Expression to verify string Composition

<Script type = "text/javascript">
Function check_str (){
Var str = document. getElementById ("str"). value;
Var check_letters =/^ [a-zA-Z] + $/. test (str); // The Judgment string is composed of letters.
Var check_numbers =/^ [0-9] + $/. test (str); // The Judgment string is composed of digits.
Var check_l_n =/^ [a-zA-Z0-9] + $/. test (str); // judge a string consisting of digits or letters
Var check_chn =/^ [\ u4E00-\ u9FA5] + $/. test (str) // The Judgment string is composed of Chinese characters.

Var result = "Pure letter:" + check_letters + "\ n pure number:" + check_numbers + "\ n letter or number:" + check_l_n + "\ n pure Chinese: "+ check_chn;
Alert (result );

If (/[^ \ x00-\ xff]/g. test (str )){
Alert ("including Chinese ")
} Else {
Alert ("not including Chinese ")
}
If (check_letters ){
Alert ("only letters ");
} Else if (check_numbers ){
Alert ("Pure digit ");
} Else if (check_l_n ){
Alert ("letters or numbers ");
} Else if (check_chn ){
Alert ("Chinese only ")
} Else {
Alert ("hybrid ");
}

}
</Script>