How to count number of characters in a line using JavaScript

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7 Answers

charactersjavascriptusingcountnumber
90%

If you ensured using a fixed-width font, you can calculate the width of a single character, e.g. using the function posted in this answer. Then, simply divide the width of the <div> through the width of a character., 2 Unless you're using a fixed-width font, there is no single number of characters that will fit into a line of a given width. – Matt Ball Nov 13 '11 at 19:02 ,You can only calculate the numbers of characters per line if the width of each character is the same. This is true for all fixed-width fonts like the one in the question editor of stackoverflow.,Asking for help, clarification, or responding to other answers.

It is definitely possible to get the number of characters you can fit on one line even if you have a proportional typeface. There are two ways—either use the following trick or the measureText method of CanvasRenderingContext2D.

var target_width = 200; // line width
var text = 'Lorem ipsum. I want to know how many chars of this text fit.';

var span = document.createElement('span');
document.body.appendChild(span);
span.style.whiteSpace = 'nowrap';
// define the style
span.style.fontFamily = 'Lucida Grande';
span.style.fontSize = '14px';

var fit = text.length;
for (var i = 0; i < fit; ++i) {
   span.innerHTML += text[i];
   if (span.clientWidth > target_width) {
      fit = i - 1;
      break;
   }
}

document.body.removeChild(span);

// fit = the number of characters of the text
//       that you can fit on one line
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88%

Regular expressions are often used in JavaScript for matching a text with a pattern. The following code example demonstrates its usage to get the count of the characters in the string. It uses the match() method of the string instance.,This post will discuss how to count the total number of occurrences of a character in a string with JavaScript.,That’s all about counting the number of occurrences of a character in a string in JavaScript.,Another alternative is to filter the array to allow only those values matching the given character. This would translate to a simple code below:

1. Using Regex

Regular expressions are often used in JavaScript for matching a text with a pattern. The following code example demonstrates its usage to get the count of the characters in the string. It uses the match() method of the string instance.

match()
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72%

Return the number of characters in a string:,The length property returns the length of a string.,The length of an empty string is 0.,length is fully supported in all browsers:

Definition and Usage

The length property returns the length of a string.

length
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65%

In the beginning, the value of the count variable is 0.,The for loop is used to iterate over the strings.,In this example, you will learn to write a JavaScript program that checks the number of occurrences of a character in a string.,During each iteration, if the character at that index matches the required character to match, then the count variable is increased by 1.

Example 1: Check Occurrence of a Character Using for Loop

// program to check the number of occurrence of a character

function countString(str, letter) {
   let count = 0;

   // looping through the items
   for (let i = 0; i < str.length; i++) {

      // check if the character is at that position
      if (str.charAt(i) == letter) {
         count += 1;
      }
   }
   return count;
}

// take input from the user
const string = prompt('Enter a string: ');
const letterToCheck = prompt('Enter a letter to check: ');

//passing parameters and calling the function
const result = countString(string, letterToCheck);

// displaying the result
console.log(result);
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75%

Write a JavaScript function that accepts two arguments, a string and a letter and the function will count the number of occurrences of the specified letter within the string. Sample arguments: 'w3resource.com', 'o' Expected output: 2 ,Previous: Write a JavaScript function to get all possible subset with a fixed length (for example 2) combinations in an array. Next: Write a JavaScript function to find the first not repeated character.,See the Pen JavaScript - Letter count within a string-function-ex- 22 by w3resource (@w3resource) on CodePen.,Because of certain maintenance issues of our servers and financial constraints, we are closing our commenting system for the time being. We may resume that in the near future.

HTML Code:

<!DOCTYPE html>
<html>

<head>
   <meta charset="utf-8">
   <title>Letter count within a string</title>
</head>

<body>

</body>

</html>

JavaScript Code:

function char_count(str, letter) {
   var letter_Count = 0;
   for (var position = 0; position < str.length; position++) {
      if (str.charAt(position) == letter) {
         letter_Count += 1;
      }
   }
   return letter_Count;
}

console.log(char_count('w3resource.com', 'o'));

Sample Output:

2
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40%

Use javascript length property to count characters in the given string. This way you will get the number of characters in a string. ,See below example how you can count the char in string using string.length property:-,I also want to map the same character as a property name in an object.,Find the count of comma , character, which is 3. And the count of individual strings after the split along with a comma, which is 4.

See below example how you can count the char in string using string.length property:-

<!DOCTYPE html>
<html>

<head>
   <title> Example</title>
   <script type="text/javascript">
      var str = "Hello World!";
      var n = str.length;
      // show output in alert
      alert(n)
   </script>
</head>

</html>
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22%

First initialize count with value 0 for ith value of string.,Now we iterate over string if ith value matches with the character, increase the count value by 1.,We iterate over string and increment value of the character.,First we initialize map with key each character of string and value for each is 0.

Given a string, our task is finding the occurrence of a character in the string with the help of user-defined function.

Example:
   Input: "hello"
Output: h occur 1 times
e ocuur 1 times
l occur 2 times
o occur 1 times
Explanation: here "hello"
have 1 h, so it have 1 value.
as same e have 1, l have 2, o have 1.
Example 2:
   Input: "did"
Output: d occur 2 times
i occur 1 times

 
Output:

h ocuurs 1 times
e ocuurs 1 times
l ocuurs 3 times
o ocuurs 2 times
w ocuurs 1 times
r ocuurs 1 times
d ocuurs 1 times

 
Output:

g occurs 2 times
f occurs 1 times
h occurs 1 times
e occurs 1 times
l occurs 2 times
o occurs 1 times
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