Work with strings

In this guide, we will explore the functional capabilities for working with strings in vein.
We'll cover string concatenation, various methods provided by the std library, and template strings.

Methods provided by the std library

string.format

The string.format method is used to create formatted strings. Here is an example:

auto name = "Alice";
auto age = 30;
auto formattedString = string.format("Name: {0}, Age: {1}", name, age);
Out.println(formattedString);  // Output: Name: Alice, Age: 30

string.startsWith

The string.startsWith method checks if a string starts with a specified prefix:

auto str = "Hello, World!";
result = string.startsWith(str, "Hello");
Out.println(result);  // Output: true

string.endsWith

The string.endsWith method checks if a string ends with a specified suffix:

auto str = "Hello, World!";
result = string.endsWith(str, "World!");
Out.println(result);  // Output: true

string.contains

The string.contains method checks if a string contains a specified substring:

auto str = "Hello, World!";
result = string.contains(str, "World");
Out.println(result);  // Output: true

string.equal

The string.equal method checks if two strings are equal:

auto str1 = "Hello";
auto str2 = "Hello";
result = string.equal(str1, str2);
Out.println(result);  // Output: true

Template Strings experimental supported only in 0.45 version

Template strings allow you to embed expressions within string literals using {} brackets and are prefixed with !. Here is an example:

auto name = "Alice";
auto age = 30;
auto templateString = !"{name} is {age} years old.";
Out.println(templateString);  // Output: Alice is 30 years old.

Template strings are particularly useful for creating complex strings that include multiple variables and expressions.

Example: Combining Various String Operations

Let's combine all these concepts into a single example:

#use "std"

class Prog {
   master(): void {
      auto name = "Alice";
      auto age = 30;
      auto greeting = "Hello, " + name + "!";

      auto formatted = string.format("Name: {0}, Age: {1}", name, age);
      auto startsWithHello = string.startsWith(greeting, "Hello");
      auto endsWithExclamation = string.endsWith(greeting, "!");
      auto containsName = string.contains(greeting, name);
      auto equalCheck = string.equal(name, "Alice");

      auto templateString = !"{name} is {age} years old.";

      Out.println("Concatenated: " + greeting);
      Out.println("Formatted: " + formatted);
      Out.println("Starts with 'Hello': " + startsWithHello);
      Out.println("Ends with '!': " + endsWithExclamation);
      Out.println("Contains name: " + containsName);
      Out.println("Name equals 'Alice': " + equalCheck);
      Out.println("Template String: " + templateString);
   }
}

In this example:

• We use concatenation to create a greeting message.
• We format a string with string.format.
• We check if the greeting starts with "Hello" using string.startsWith.
• We check if the greeting ends with "!" using string.endsWith.
• We check if the greeting contains the name using string.contains.
• We check if the name is equal to "Alice" using string.equal.
• We create a template string that embeds variables within the string.

Each method and concept provides powerful ways to work with strings in vein.

Conclusion

Now that you know how to work with strings, including concatenation, using various std library methods, and template strings, you can efficiently handle text in your programs. Experiment with these features to become more familiar with their capabilities.