String Classes

String

String class provides an extensive set of APIs for working with UTF-8 strings, including method for comparing, searching, and other string operations. Behind the scenes, String uses implicit sharing (copy-on-write) to reduce memory usage and to avoid the needless copying of data.

It can be encoded and decoded to and from UTF-8, UTF-16, UTF-32.

String16

String16 class is working with UTF-16 strings. All member functions are smiliar with String class.

Creating and Formatting the String

The most common and the one you are likely to be using is String::format()

String name = "Johne"
String message = String::format("Hello, %s!, You have %d new messages.", name, 20);

String formatting is smiliar with Java Formatter. Take a look at the Java documentation on java.util.Formatter

You can also get the length of a string which can be obtained using getLength() method:

String str = "SLib.io is so great!"
int length = str.getLength();

Comparing Strings

You can compare strings using equals() and compare() methods or comparison operators.

String str = "SLib.io is so great!"

if (!str.equals("SLib.io is so fantastic!")) {
   Console::println("No, They aren't both equal");
}

if (str == "SLib.io is so great!") {
   Console::println("Yes, They are both equal");
}

if (str > "SLib.io is so fantastic!" || str < "SLib.io is so fantastic!") {
   Console::println("No, They aren't both equal");
}

if (str.compare("SLib.io is so great!") == 0) {
   Console::println("Yes, They are both equal");
}

Combining Strings

You can combine strings using Concatenation operator.

String str1 = "SLib.io"
String16 str2 = "はとても素晴らしいです！"
String str3 = str1 + str2;
Console::println(str3);
str1 += str2;
Console::println(str1);

Searching Strings

You can use indexOf() method to find out whether a substring exists.

String str = "SLib.io is so great!"
int index = str.indexOf("great");
if (index < 0) {
   Console::println("Search string was not found");
} else {
   Console::println("'great' starts at index %d", index);
}

Splitting Strings into an Array

You can use a method called split() to achieve this:

String str = "SLib.io is so great!";
List<String> words = str.split(" ");

for (String& word: words) {
   Console::println(word);
}

You can use auto specifier instead of List<String>:

String str = "SLib.io is so great!";
auto words = str.split(" ");

for (auto& word: words) {
   Console::println(word);
}

Replacing Substrings

You can use replaceAll() method.

String str = "SLib.io is so great!";
String str1 = str.replaceAll("great", "fantastic");

Changing Case

String classes provide a few convenient methods for changing the case of a string. This can be used to normalize user submitted values.

String str1= "hElLo wOrLD"
Console::println("%s, %s", str1.toUpper(), str1.toLower());
// Prints: HELLO WORLD, hello world

Numerical Conversions

String classes define several conversion methods for interpreting strings as primitive values.

String age = "25"
int value1 = str1.parseInt();

String hexString = "0f0c0d0b0ffff"
long long value2 = hexString.parseInt64(16);