The String object's length property

The String object's length property returns the number of characters in a string.

Syntax

string.length

Parameters

Not applicable. The length property does not accept any parameters since it is a property, not a method.

Return value

The length property returns a number representing the number of characters in the string.

Examples

Example 1: The length property returns the total number of characters in a string

In the code below, the function lengthEx1() logs the number of characters in different strings.

function lengthEx1() {
  let str1 = "Hello world!";
  let str2 = ""; // Empty string
  let str3 = " "; // String with one space
  
  // counts all characters including spaces
  Logger.log(str1.length);
  
  // empty string has zero length
  Logger.log(str2.length);
  
  // space is counted as a character
  Logger.log(str3.length);
}

Output

12.0

0.0

1.0

Example 2: The length property counts special characters and Unicode characters

In the code below, the function lengthEx2() demonstrates how the length property counts special characters and Unicode characters.

function lengthEx2() {
  let str1 = "Hello\nWorld"; // String with newline
  let str2 = "🌍World"; // String with emoji
  
  // newline counts as one character
  Logger.log(str1.length);
  
  // emoji counts as 2 characters
  Logger.log(str2.length);
}

Output

11.0

7.0

Example 3: Using length property for string validation

In the code below, the function validateString() uses the length property to check if a string meets certain length requirements.

function validateString() {
  let username = "user123";
  let password = "pass";
  
  // Check if username is between 6 and 12 characters
  if (username.length >= 6 && username.length <= 12) {
    Logger.log("Username length is valid");
  } else {
    Logger.log("Username must be between 6 and 12 characters");
  }
  
  // Check if password is at least 8 characters
  if (password.length >= 8) {
    Logger.log("Password length is valid");
  } else {
    Logger.log("Password must be at least 8 characters");
  }
}

Output

Username length is valid Password must be at least 8 characters

function modifyLength() {
  let str = "Hello";
  str.length = 10; // This will have no effect
  Logger.log(str.length); // Still outputs 5
}

Conclusion

In this tutorial, you learned how to use the length property of the String object to determine the number of characters in a string. This property is particularly useful for string validation and text processing tasks in Apps Script.