Using JavaScript, How to get a Y-letter count from a sentence X number of times?

Question

I'm trying to create a little tool that when a user enters a sentence, and then a specify letter, it takes that letter and counts it in the sentence above entered by the user and displays the number of times the letter appears in the sentence.

let sentence = document.getElementById("textbox1")
let character = sentence.value
let letter = document.getElementById("textbox2")
let getLetter = letter.value
var exampleString = character
document.getElementById("parseString").onclick = letterCount;
function letterCount(string, letter, caseSensitive) {
  var count = 0;
  if (!caseSensitive) {
    string = string.toUpperCase();
    letter = letter.toUpperCase();
  }
  for (var i = 0, l = string.length; i < string.length; i += 1) {
    if (string[i] === letter) {
      count += 1;
    }
  }
  return count;
}
let display = (letterCount(character, getLetter, true));
document.getElementById("output1").innerHTML

<p>Enter a sentence: <input type="text" id="textbox1"></p>
<p>Enter a letter: <input type="text" id="textbox2"></p>
<button id="parseString">Parse String</button>
<p id="output1">The letter appears in the string</p>

I'm still new to JavaScript and still learning how to code and nest certain things properly.

Can you fix your snippet so that it runs? `Uncaught SyntaxError: Unexpected string` — CertainPerformance, Mar 15 '19 at 08:44
The code seems to be working, maybe it's a little ugly and it could use some cleanup, but what exactly is your question? — ChatterOne, Mar 15 '19 at 08:47
@ChatterOne my question is how can I so that when a user enters a sentence lets say "StackOverflow" and then enters "o" in the 2nd textbox, and the output shows "The letter O appears 2 times" — Michael Kheong, Mar 15 '19 at 08:52
I think this might be a duplicate of https://stackoverflow.com/questions/4009756/how-to-count-string-occurrence-in-string — C.Gibby, Mar 15 '19 at 08:55
@C.Gibby theirs is using a string but I would like it to get the value from textbox1 that the user enters a sentence — Michael Kheong, Mar 15 '19 at 08:56
@MichaelKheong You should be able to use sentence.value to get the textbox value in your code. — C.Gibby, Mar 15 '19 at 09:00

nerding_it · Accepted Answer · 2019-03-15T09:22:34.693

Cleaned up your code, Some of the variables in top must be inside your event handler

document.getElementById("parseString").onclick = function() {
  let character = document.getElementById("textbox1").value;
  let getLetter = document.getElementById("textbox2").value;
  let count = letterCount(character, getLetter, true);
  document.getElementById("output1").innerHTML = `The letter '${getLetter}' appears in the string '${character}' ${count} times`;
}

function letterCount(string, letter, caseSensitive) {
    regexp = caseSensitive ? new RegExp(letter, 'g') : new RegExp(letter, 'gi');
    return string.match(regexp).length;
}

<p>Enter a sentence: <input type="text" id="textbox1"></p>
<p>Enter a letter: <input type="text" id="textbox2"></p>
<button id="parseString">Parse String</button>
<p id="output1">The letter appears in the string</p>

I'd at least add a `;` to the line endings (quite a few are missing), also `exampleString` is never used — ChatterOne, Mar 15 '19 at 09:03

Using JavaScript, How to get a Y-letter count from a sentence X number of times?

1 Answers1