如何执行所有可能的组合？

Question

I've got this code below that generates a random 5-character code. For example AU330 , UEEHB , 2EH8D HJ1LM .

function makeid(length) {
   var result           = ''
   var characters       = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
   var charactersLength = characters.length;
   for ( var i = 0; i < length; i++ ) {
      result += characters.charAt(Math.floor(Math.random() * charactersLength))
   }
   return result
}

alert(makeid(5)); 

What I want to do is check each possible code for U330 and for each code that contains it, log it to console.

Expected Output:

AU330

BU330

CU330

DU330

...

Answer 1

You could simply search for a substring with indexOf() function or check for the exact string with regular expressions.

var input = "AU330";

console.log(input.indexOf("U330") !== -1); //Indexof
console.log(/[A-Z0-9]U330/.test(input)); //Regex