jQuery / JS - Detecting / Matching an URL string to determine it's type

You can use a regex for the check, for example:

if(/\/items\/\d+/.test(url)) {
  //type B
} else if (/\/items/.test(url)) {
  //type A
}

This checks for the number version first, if that fails it checks for at least /items...if you're assured it's one or the other you can leave off the second if and just use the else.

You can split the pathname on /, and do a parseInt() on the last item in the Array.

if( parseInt( location.pathname.split('/').pop() ) ) {
    // was a successful number, so type B
} else {
    // was NaN, so type A
}

If it was successfully parsed as a number, it was type B, otherwise, type A.

Note that this will fail if you have the number 0 for the number. If 0 is a possibility, then you could just add 1 to the number.

if (type == '/items'){
  // Type A
} else if (type.match('/\/items\/[0-9]+/')){
  //Type B
} else {
  //Not either of the two
}

You can just match the string for the first part, the 2nd part could require regex if you need a third condition, otherwise, it's

if (type == '/items'){
  //A
} else {
  //B, (or anything else)
}

// /items/1233
if (url.match('\\/items/\\d+'))
{

}
// /items/
else if (url.match('\\/items/'))
{

}