@rbxts/jsnatives

endsWith

Determines whether a string ends with the characters of a specified string.

Signature

function endsWith(str: string, search: PatternAdmissible, position?: NumericAdmissible): boolean

Description

The endsWith function checks if a string ends with a specified substring. It returns true if the string ends with the specified characters, and false otherwise. The search is case-sensitive.

Parameters

str: The string to check.
search: The characters to search for at the end of the string. Can be a string, number, or boolean.
position (optional): The position in the string at which to stop searching. Default is the string length. If a string is provided, it will be converted to a number.

Return value

true if the string ends with the specified characters.
false otherwise.

Examples

Basic usage

// Check if a string ends with a substring
const endsWithWorld = String.endsWith("Hello world", "world");
print(endsWithWorld); // Outputs: true

const endsWithHello = String.endsWith("Hello world", "Hello");
print(endsWithHello); // Outputs: false

With position parameter

// Check up to a specific position
const text = "Hello world";
const endsWitho = String.endsWith(text, "o", 5);
print(endsWitho); // Outputs: true (checks only in "Hello")

// The position marks the end of the considered string
const endsWitho2 = String.endsWith(text, "o", 6);
print(endsWitho2); // Outputs: false (checks only in "Hello " including space)

Using non-string values

// Checking with a number (converted to string)
const endsWithNumber = String.endsWith("The answer is 42", 42);
print(endsWithNumber); // Outputs: true

// Checking with a boolean (converted to string)
const endsWithBoolean = String.endsWith("The value is true", true);
print(endsWithBoolean); // Outputs: true

Case sensitivity

// The check is case-sensitive
const text = "Hello World";
const endsWithworld = String.endsWith(text, "world");
print(endsWithworld); // Outputs: false

const endsWithWorld = String.endsWith(text, "World");
print(endsWithWorld); // Outputs: true

Practical applications

// Check if a filename has a specific extension
function hasExtension(filename: string, extension: string): boolean {
  // Make sure extension starts with a dot
  if (!String.startsWith(extension, ".")) {
    extension = `.${extension}`;
  }

  return String.endsWith(filename, extension);
}

print(hasExtension("document.pdf", "pdf")); // Outputs: true
print(hasExtension("image.jpg", ".jpg")); // Outputs: true
print(hasExtension("script.ts", "js")); // Outputs: false

// check if git page is valid
function isValidGitPage(url: string): boolean {
  return String.endsWith(url, ".git") || String.endsWith(url, ".github.io");
}

print(isValidGitPage("https://github.com/RsMan-Dev/rbxts-jsnatives.git")); // Outputs: true
print(isValidGitPage("https://example.com")); // Outputs: false