Strings

Utah provides powerful built-in functions for working with strings, making text manipulation intuitive and type-safe.

Strings

String Declaration and Initialization

// Basic string declaration
let message: string = "Hello, Utah!";

// Empty string
let empty: string = "";

// String with special characters
let path: string = "/usr/local/bin";

String Methods

string.length()

Get the length of a string:

let message: string = "Hello, Utah!";
let len: number = string.length(message);
console.log("Message length: ${len}");

string.contains()

Check if a string contains a substring:

let filepath: string = "/home/user/script.shx";

if (string.contains(filepath, ".shx")) {
  console.log("This is a Utah script file");
}

string.startsWith()

Check if a string starts with a prefix:

let url: string = "https://api.example.com";

if (string.startsWith(url, "https://")) {
  console.log("Secure connection");
}

string.endsWith()

Check if a string ends with a suffix:

let filename: string = "backup.tar.gz";

if (string.endsWith(filename, ".tar.gz")) {
  console.log("This is a compressed archive");
}

string.split()

Split a string into an array:

let path: string = "/usr/local/bin";
let parts: string[] = string.split(path, "/");
// parts is ["", "usr", "local", "bin"]

string.replace()

Replace first occurrence of a substring:

let message: string = "Hello, World!";
let updated: string = string.replace(message, "World", "Utah");
// updated is "Hello, Utah!"

string.replaceAll()

Replace all occurrences of a substring:

let text: string = "hello hello world";
let updated: string = string.replaceAll(text, "hello", "hi");
// updated is "hi hi world"

string.trim()

Remove whitespace from both ends:

let input: string = "  hello world  ";
let clean: string = string.trim(input);
// clean is "hello world"

string.toUpperCase() and string.toLowerCase()

Change case:

let name: string = "Utah";
let upper: string = string.toUpperCase(name);  // "UTAH"
let lower: string = string.toLowerCase(name);  // "utah"

string.capitalize()

Capitalize the first letter of a string:

let name: string = "john";
let capitalized: string = string.capitalize(name);  // "John"

string.substring() and string.slice()

Extract parts of a string:

let text: string = "JavaScript";

// substring(start, end) - extracts from start index to end index
let sub: string = string.substring(text, 0, 4);  // "Java"

// slice(start, end) - similar to substring but supports negative indices
let sliced: string = string.slice(text, 4, 10);  // "Script"

string.indexOf()

Find the position of a substring:

let text: string = "The quick brown fox";
let position: number = string.indexOf(text, "brown");  // 10
let notFound: number = string.indexOf(text, "cat");    // -1

string.padStart() and string.padEnd()

Add padding to strings:

let num: string = "42";

// Pad start with zeros to make it 5 characters
let padded: string = string.padStart(num, 5, "0");  // "00042"

// Pad end with dashes to make it 5 characters
let paddedEnd: string = string.padEnd(num, 5, "-");  // "42---"

string.repeat()

Repeat a string multiple times:

let pattern: string = "abc";
let repeated: string = string.repeat(pattern, 3);  // "abcabcabc"

string.isEmpty()

Check if a string is empty:

let text: string = "";
let whitespace: string = "   ";

let empty: boolean = string.isEmpty(text);        // true
let notEmpty: boolean = string.isEmpty(whitespace); // false

String Interpolation

Use template literals for dynamic strings:

let name: string = "Alice";
let age: number = 30;
let message: string = "Hello, ${name}! You are ${age} years old.";

Common String Patterns

File Path Processing

let filePath: string = "/home/user/documents/report.pdf";

if (string.contains(filePath, "/home/")) {
  console.log("File is in user directory");
}

if (string.endsWith(filePath, ".pdf")) {
  console.log("This is a PDF file");
}

let pathParts: string[] = string.split(filePath, "/");
let fileName: string = pathParts[array.length(pathParts) - 1];
console.log("File name: ${fileName}");

URL Processing

let url: string = "https://api.example.com/v1/users";

if (string.startsWith(url, "https://")) {
  console.log("Secure URL");
}

let urlParts: string[] = string.split(url, "/");
let domain: string = urlParts[2];
console.log("Domain: ${domain}");

Text Processing

let input: string = "  Hello, World!  ";
let cleaned: string = string.trim(input);
let upperCase: string = string.toUpperCase(cleaned);
let replaced: string = string.replace(upperCase, "WORLD", "UTAH");

console.log("Result: ${replaced}"); // "HELLO, UTAH!"

Advanced String Manipulation

// Working with user input
let userName: string = "john_doe";
let displayName: string = string.capitalize(string.replace(userName, "_", " "));
console.log("Welcome ${displayName}!"); // "Welcome John doe!"

// Formatting numbers
let number: string = "42";
let padded: string = string.padStart(number, 6, "0");
console.log("Order #${padded}"); // "Order #000042"

// Creating patterns
let separator: string = string.repeat("-", 20);
console.log(separator); // "--------------------"

// Text analysis
let sentence: string = "The quick brown fox jumps over the lazy dog";
let wordPosition: number = string.indexOf(sentence, "fox");
let excerpt: string = string.substring(sentence, wordPosition, wordPosition + 3);
console.log("Found '${excerpt}' at position ${wordPosition}");

Configuration Parsing

let config: string = "debug=true,port=8080,host=localhost";
let pairs: string[] = string.split(config, ",");

for (let pair: string in pairs) {
  let keyValue: string[] = string.split(pair, "=");
  if (array.length(keyValue) == 2) {
    let key: string = string.trim(keyValue[0]);
    let value: string = string.trim(keyValue[1]);
    console.log("${key}: ${value}");
  }
}

String Validation

function validateInput(input: string): boolean {
  // Check if string is empty
  if (string.isEmpty(input)) {
    console.log("Input cannot be empty");
    return false;
  }

  // Check if string is only whitespace
  if (string.isEmpty(string.trim(input))) {
    console.log("Input cannot be only whitespace");
    return false;
  }

  return true;
}

function isValidIdentifier(name: string): boolean {
  // Check for valid identifier pattern
  if (string.contains(name, " ")) {
    return false;
  }

  if (string.startsWith(name, "_") || string.startsWith(name, "-")) {
    return false;
  }

  return true;
}

let userInput: string = "my_variable";
if (validateInput(userInput) && isValidIdentifier(userInput)) {
  console.log("Valid identifier: ${userInput}");
}

Text Formatting and Cleanup

// Clean and format text data
let rawData: string = "  JavaScript, Python, TypeScript  ";
let languages: string[] = string.split(rawData, ",");

for (let lang: string in languages) {
  let cleaned: string = string.trim(lang);
  let formatted: string = string.capitalize(string.toLowerCase(cleaned));
  console.log("Language: ${formatted}");
}

// Replace multiple patterns
let messyText: string = "Hello... world!!! How are you???";
let step1: string = string.replaceAll(messyText, "...", ".");
let step2: string = string.replaceAll(step1, "!!!", "!");
let step3: string = string.replaceAll(step2, "???", "?");
console.log("Cleaned: ${step3}");

Log Processing

let logLine: string = "2024-01-15 14:30:22 INFO User logged in successfully";
let parts: string[] = string.split(logLine, " ");

if (array.length(parts) >= 4) {
  let date: string = parts[0];
  let time: string = parts[1];
  let level: string = parts[2];
  let message: string = string.join(array.slice(parts, 3), " ");

  console.log("Date: ${date}, Time: ${time}, Level: ${level}");
  console.log("Message: ${message}");
}

String Type Safety

Strings in Utah are strongly typed:

// Type-safe string operations
let message: string = "Hello";
let length: number = string.length(message);  // Always returns number

// This would cause a compile error:
// let invalid: string = 123;  // Error: Cannot assign number to string

String Performance Tips

1. Use string interpolation instead of repeated concatenation
2. Cache string lengths in loops to avoid repeated calculations
3. Use specific methods for your use case (contains vs startsWith/endsWith)
4. Avoid unnecessary string operations in performance-critical code

String Error Handling

Always validate inputs when working with strings:

function processString(input: string): void {
  if (string.length(input) == 0) {
    console.log("Warning: Empty string provided");
    return;
  }

  let trimmed: string = string.trim(input);
  if (string.length(trimmed) == 0) {
    console.log("Warning: String contains only whitespace");
    return;
  }

  // Process string
  console.log("Processing: ${trimmed}");
}

String Formatting

Template Literals

Use template literals for complex string formatting:

let user: string = "Alice";
let action: string = "login";
let timestamp: string = "2024-01-15 14:30:22";

let logMessage: string = "[${timestamp}] User '${user}' performed action: ${action}";
console.log(logMessage);

Conditional String Building

let environment: string = "production";
let debugMode: boolean = false;

let config: string = "Environment: ${environment}";
if (debugMode) {
  config = "${config}, Debug: enabled";
} else {
  config = "${config}, Debug: disabled";
}

console.log(config);

Email Validation

function isValidEmail(email: string): boolean {
  // Check if empty or only whitespace
  if (string.isEmpty(email) || string.isEmpty(string.trim(email))) {
    return false;
  }

  // Basic email validation
  if (!string.contains(email, "@")) {
    return false;
  }

  if (!string.contains(email, ".")) {
    return false;
  }

  let emailParts: string[] = string.split(email, "@");
  if (array.length(emailParts) != 2) {
    return false;
  }

  let localPart: string = emailParts[0];
  let domainPart: string = emailParts[1];

  if (string.isEmpty(localPart) || string.isEmpty(domainPart)) {
    return false;
  }

  return true;
}

let email: string = "user@example.com";
if (isValidEmail(email)) {
  console.log("Valid email: ${email}");
} else {
  console.log("Invalid email: ${email}");
}

String Escaping

Handle special characters in strings:

// Strings with quotes
let message: string = "She said, \"Hello, world!\"";

// Strings with backslashes
let path: string = "C:\\Users\\Alice\\Documents";
let regexPattern: string = "\\d+\\.\\d+";

Strings form the foundation of text manipulation in Utah, providing type-safe operations with familiar syntax and powerful built-in functions for common text processing tasks.