如何在字符串中搜索字符串数组中包含的所有值？ （JavaScript）的

Question

I am trying to learn if there is a javascript method to search a string to see if that string contains any of the values in an array of strings.

An example would be:

var a = 'How now brown cow';
var b = new Array('red', 'green', 'brown');

The resulting function would return true because the word brown is contained within the string a .

More specifically what I am trying to do (except using values from form input) is:

var a = '12345@gmail.com';
var b = new Array('.com', '.net', '.org');

This should also return true. Then based on this I will go on to accept var a as valid.

My actual code as of right now (which always returns null ) is as follows:

function check_domain(){
  for(var i=0; i<domains.length; i++){
    var d = domains[i];
    if(elemen.value.indexOf(d) != d){
      return null;
    }
    else{
      vEmail.style.visibility = 'visible';
    }
  }
}

  window.domains = new Array(....Array values here....);

Answer 1

You can create a regular expression from the array:

var re = new RegExp(domains.join('|').replace(/\./g,'\\.'));

Then you can test a string:

var a = '12345@gmail.com';
var found = re.test(a);

Answer 2

Not sure why you've got .indexOf(d) != d . Shouldn't it be:

function check_domain(){
   var d, i;
   for(i = 0; i < domains.length; i++){
      d = domains[i];
      if(elemen.value.indexOf(d) != -1) {
        return true;
      }
   }
}

Answer 3

Yes, there is something called Regular Expressions, if you really need it to match values in an array you can create a loop and check for each word against the string, something like this:

var a = 'How now brown cow';
var b = new Array('red', 'green', 'brown');

function Check(target, lookFor)
{
    for(var I = 0, L = lookFor.length; I <= L; I++)
        if(new RegExp(lookFor[I]).test(target))
            return true;
    return false;
}

alert(Check(a, b));

But in your case, the best way to go about this is just to join all the words you want to look for in the target string inside only one regular expression, so you avoid using a loop.

if(/(\.com|\.net|\.org)$/.test("sfdsdfsdf@gmail.com"))
{
// Valid email
}
else
{
// Invalid email
}