javascript - Generating unique 6 digit code js -

i trying generate 6 digit code using js.

it must contains 3 digits , 3 chars.

here code

var numbers = "0123456789"; var chars = "acdefhiklmnoqrstuvwxyz"; var string_length = 3; var randomstring = ''; var randomstring2 = ''; (var x = 0; x < string_length; x++) {     var letterornumber = math.floor(math.random() * 2);     var rnum = math.floor(math.random() * chars.length);     randomstring += chars.substring(rnum, rnum + 1); } (var y = 0; y < string_length; y++) {     var letterornumber2 = math.floor(math.random() * 2);     var rnum2 = math.floor(math.random() * numbers.length);     randomstring2 += numbers.substring(rnum2, rnum2 + 1); } var code = randomstring + randomstring2; 

the code result 3chars + 3 numbers .. want rearrange value random value contains same 3 chars , 3 numbers

http://jsfiddle.net/pgdfq/101/

you shuffle current codes function (from this answer)

//+ jonas raoni soares silva //@ http://jsfromhell.com/array/shuffle [v1.0] function shuffle(o){ //v1.0     for(var j, x, = o.length; i; j = math.floor(math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);     return o; }; 

you use this:

alert(shuffle("stackoverflow".split('')).join('')); 

here updated demo code.