如何编写一个称为countDots（x）的函数，该函数将字符串作为参数并返回包含的点数（。）。

Question

I have recently started learning coding and am trying to learn how to create functions but I am finding it quite difficult.

How would write a function called countDots(x) that takes a string as an argument and returns the number of dots (.) it contains.Eg x = "www.google.com" the function will return with 2.

Answer 1

I would do it this way:

 function dotCounter(x) { return x.split('.').length -1; } document.write( dotCounter("www.google.com") ); 

Answer 2

Please try this

function countDots(x){
    return((x.match(/\./g) || []).length)
}

Answer 3

As you say you're learning to code at the moment, you don't need speed-optimised code. I'd suggest this - it only use ideas that turn up in almost all programming languages:

function countDots(str) {
  var count = 0;
  for (var x = 0; x < str.length; x++) {
    if str.charAt(x) == '.' {
      count++;
    }
  }
  return count;
}

You can worry about speed once you're happy that you've got the basics! Good luck