Counting upper and lower case characters in a string
Question
First off, I know this is far from professional. I'm trying to learn how to work with strings. What this app is supposed to do is take a simple text input and do a few things with it:
count letters, count upper and lower case letters, count words and count spaces. Here is what I've done:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Case Check</title>
<script type="text/javascript">
function checkCase(text)
{
var counter = 0;
var letters = 0;
var lowercase = 0;
var uppercase = 0;
var spaces = 0;
var words = 0;
for(; counter < text.length; counter++)
{
if(isUpperCase(text.charAt(counter))) {uppercase ++; letters++;}
if(isLowerCase(text.charAt(counter))) {lowercase ++; letters++;}
if((text.charAt(counter) == " ") && (counter < text.length))
{
spaces += 1;
words += 1;
}
if((text.charAt(counter) == ".") || (text.charAt(text(counter)) == ",")) continue;
}
return [letters, lowercase, uppercase, spaces, words];
}
function isUpperCase(character)
{
if(character == character.toUpperCase) return true;
else return false;
}
function isLowerCase(character)
{
if(character == character.toLowerCase) return true;
else return false;
}
</script>
</head>
<body>
<script type="text/javascript">
var typed = prompt("Enter some words.");
var result = checkCase(typed);
document.write("Number of letters: " + result[0] + "br /");
document.write("Number of lowercase letters: " + result[1] + "br /");
document.write("Number of uppercase letters: " + result[2] + "br /");
document.write("Number of spaces: " + result[3] + "br /");
document.write("Number of words: " + result[4] + "br /");
</script>
</body>
Made several changes due to users' suggestions. The problem now is that it won't let me treat 'text' like a string object.
7 answers
solution1
17 2014-04-18 20:12:14
Use regular expressions.
Example
var s = "thisIsAstring";
var numUpper = s.length - s.replace(/[A-Z]/g, '').length;
// numUpper = 2
Se more at JavaScript replace/regex
solution2
8 2017-06-11 11:55:21
You can use match() and regular expressions.
var str = "aBcD";
var numUpper = (str.match(/[A-Z]/g) || []).length; // 2
solution3
2 ACCPTED 2013-10-04 00:33:27
Not sure if whole problem, but bad paren on this one
if(text.charAt(letters)) == " " && text(letters) < text.length)
^
Should be
if(text.charAt(letters) == " ") && text(letters) < text.length)
^
And actually I'd make it
if((text.charAt(letters) == " ") && (text(letters) < text.length))
solution4
2 2013-10-04 01:18:56
isUpperCase and isLowerCase are not JavaScript functions.
You can replace them with something like
var isUpperCase = function(letter) {
return letter === letter.toUpperCase();
};
var isLowerCase = function(letter) {
return letter === letter.toLowerCase();
};
There were a lot of syntax errors in your code which you need to check.
I was also getting confused with all your brackets so instead of using the charAt I just referenced the string like an array. So instead of text.charAt(letters) I used text[letters] which I found easier to read.
See the full jsFiddle here . I modified your code slightly because jsFiddle doesn't allow document.write
solution5
2 2020-03-15 20:46:01
Another solution using CharCodeAt() method.
const bigLettersCount = (str) => {
let result = 0;
for (let i = 0; i < str.length; i += 1) {
if (str.charCodeAt(i) > 64 && str.charCodeAt(i) <91 ) {
result += 1;
}
}
return result
}
console.log(bigLettersCount('Enter some words.'))
solution6
1 2020-03-15 20:28:49
Another solution is using Array.from() make an array which includes each character of str and then using reduce() to count the number of the uppercase letters.
const str = 'HeLlO'; const res = Array.from(str).reduce((acc, char) => { return acc += char.toUpperCase() === char; }, 0); console.log(res);
solution7
0 2019-10-16 17:02:28
Most of the solutions here will fail when string contains UTF8 or diacritic characters. An improved version that works with all strings can be found at the turbocommons library, here:
Example:
// Returns 2
StringUtils.countByCase('1声A字43B45-_*[]', StringUtils.FORMAT_ALL_UPPER_CASE);
// Returns 1
StringUtils.countByCase('1声A字43B45a-_*[]', StringUtils.FORMAT_ALL_LOWER_CASE);
More info here:
Play with it online here:
https://turbocommons.org/en/app/stringutils/count-capital-letters
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