Count number of characters

Counting number of characters (or bytes) in different approaches

Character Count vs. Byte Count Comparison

String example	Number of characters	Number of bytes
fox	3	3
The quick brown fox jumps over the lazy dog	43	43
狐	1	3
象	1	3
🐘	1	4
敏捷的棕毛狐狸從懶狗身上躍過	14	42

Each Chinese character is approximately 3 bytes in UTF-8

Common Chinese characters (CJK Unified Ideographs, U+4E00 ~ U+9FFF) are all 3 bytes — for example, "你", "好", "狐", and "象". Characters beyond U+FFFF (outside the Basic Multilingual Plane, BMP) take 4 bytes. These are mostly rare characters from CJK Extension B (U+20000 and up), such as "𤆬" (U+241AC) and "𠮷" (U+20BB7).

How to count characters with PHP

• PHP: strlen & PHP mb_strlen function

Number of characters

echo mb_strlen("狐", 'UTF-8') . PHP_EOL; // return 1
echo mb_strlen("《王大文 Dawen》", 'UTF-8') . PHP_EOL; // return 11

String length (number of bytes)

echo strlen("狐") . PHP_EOL; // return 3
echo strlen("《王大文 Dawen》") . PHP_EOL; // return 21

Number of words str_word_count function not support Chinese characters

echo str_word_count("The quick brown fox jumps over the lazy dog"); // return 9
echo str_word_count("敏捷的棕毛狐狸從懶狗身上躍過"); // return 0

How to count characters with MySQL

• MySQL: MySQL CHAR_LENGTH() function

// number of characters
SELECT CHAR_LENGTH("狐"); /* return 1 */
SELECT CHAR_LENGTH("《王大文 Dawen》"); /* return 11 */

// number of bytes
SELECT LENGTH("狐"); /* return 3 */
SELECT LENGTH("《王大文 Dawen》"); /* return 21 */

• MySQL :: MySQL 8.0 Reference Manual :: 11.4.1 The CHAR and VARCHAR Types e.g. VARCHAR(5) or CHAR(5) means can hold up to 5 characters.

How to count characters with SQLite

Length function

SELECT LENGTH("狐"); /* return 1 */
SELECT LENGTH("《王大文 Dawen》"); /* return 11 */

How to count characters with Excel

• Excel: LEN, LENB functions / LEN、LENB 函數 Result of the function LENB is not the same with the result in other programming language.

// number of characters
=LEN("狐") // return 1
=LEN("《王大文 Dawen》") // return 11

// number of bytes
=LENB("狐") // return 2
=LENB("《王大文 Dawen》") // return 16

• Calculate String Length Online
• string - How many bytes does one Unicode character take? - Stack Overflow

How to count characters with BASH

Step1: Using Linux wc command

# Count the total number of characters in a file named "input.txt", while ignoring all whitespace characters (including spaces, tabs, newlines, etc.).
tr -d '\r\n[:space:]' < input.txt | wc -m

# print the character counts of txt files (contains the count of return symbol)
wc -m *.txt

# print the newline counts of txt files
wc -l *.txt

# print the whitespaces counts of txt files
grep -c ' ' *.txt

Step2: Check the Return symbol

• e.g. \r\n costs 2 characters

Step3: final formula

Number of characters (not contains the return symbol) = result of wc -m *.txt - result of wc -m *.txt * 2 - 1 (the last blank line costs 1 character) - number of the whitespaces

How to count characters with Python

Using the len() function. Try it on replit.

Get the number of characters in a string in Python

string = "狐"
print(len(string))
// returns 1

Get the number of bytes in a string in Python

string = "狐"
print(len(string.encode('utf-8')))
// returns 3

print(len(string.encode('utf-16-le')))
// returns 2

How to count characters with JavaScript

Using the length() function and Blob object .

Get the number of characters in a string in JavaScript

var string = "狐"
console.log(string.length);

Get the number of bytes in a string in JavaScript

var string = "狐"
console.log(new Blob([string]).size);
// returns 3

Further reading

• Unicode與JavaScript字串 | iThome