JavaScript中的正则表达式无效

Question

Regular expression not able to read complete string, only working correct with single character.

var abc = "ab";
var patter = /^([a-z0-9A-Z])$/;

 if (patter.test(abc)) {
    console.log('yes');
 } else {
   console.log('no');
} 

Answer 1

You must set a quantifier when you don't want just one character.

Add a * to match zero or more character (or a + if you want to be sure there's at least one character);

var patter = /^[a-z0-9A-Z]*$/;

Note that I removed the parentheses : they're useless with the test method.