Two string - JavaScript - using string to contain 26 characters, then look up each one in two string, use Array.indexOf method

Twostring12.cs

function processData(input) {
    var inputs = input.split("\n");
    var numberOfTestCases = inputs[0];
    for (var i = 1; i < inputs.length; i += 2)
    {
        var first = inputs[i];
        var second = inputs[i + 1];
        if (commonSubstring(first, second))
        {
            console.log("YES");
        }
        else
        {
            console.log("NO");
        }
    }
} 

function commonSubstring(first, second)
{
    var alphabet = "abcdefghijklmnopqrstuvwxyz";
    for (var i = 0; i < 26; i++)
    {
        var character = alphabet[i];
        if (first.indexOf(character) > -1 && second.indexOf(character) > -1)
        {
            return true;
        }
    }
    return false;
}

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});