# String Class

* <https://www.journaldev.com/16928/java-string>
* <https://www.java67.com/2018/01/10-important-points-about-string-in-java.html>
* <https://javarevisited.blogspot.com/2013/07/java-string-tutorial-and-examples-beginners-programming.html>

## format

* New lines
  * String.format("Hallo%n") inserts an operating system specific line break. The result differs depending on the operating system on which your program is running.
  * String.format("Hallo\n") always inserts a Linux line break regardless of the operating system.
  * Best to use \n instead

## Concatenation

* <https://pellegrino.link/2015/08/22/string-concatenation-with-java-8.html>

## Splitting

* <https://www.java67.com/2019/12/difference-between-stringtokenizer-and.html>

## String, String Builder & String buffer

* <https://www.java67.com/2014/05/difference-between-stringbuilder-and-StringBuffer-java.html>
* <https://www.java67.com/2012/08/difference-between-string-and-stringbuffer-in-java.html>

## Operations

* <https://www.javacodegeeks.com/2017/09/overview-functional-programming.html>

```java
String output;

        // replace one placeholder
        output = String.format("Hello %s", "Alex");
        System.out.println(output); // Hello Alex

        // replace multiple placeholders of different types
        output = String.format("The %s costs $%f", "Bag", 12.99f);
        System.out.println(output); // The Bag costs $12.990000

        // format number to two-decimal places
        output = String.format("The %s costs $%.2f", "Bag", 12.99f);
        System.out.println(output); // The Bag costs $12.99

        // add comma number separator
        output = String.format("The %s costs $%,.2f", "Car", 54999.99f);
        System.out.println(output); // The Car costs $54,999.99

        // Enclose a negative numbers with parenthesis
        output = String.format("Absolute zero is %(.2f degrees Celsius", -273.15f);
        System.out.println(output); // Absolute zero is (273.15) degrees Celsius

        // Positive/negative numbers
        output = String.format("Temperature of the Sun %,+d K", 5778);
        System.out.println(output); // Temperature of the Sun +5,778 K

        output = String.format("Temperature of Jupiter %,+d K", -145);
        System.out.println(output); // Temperature of Jupiter -145 K

        // A padded number
        output = String.format("A padded number %010d", 42);
        System.out.println(output); // A padded number 0000000042

        // A left-justified number
        output = String.format("A left-justified number <%-10d>", 42);
        System.out.println(output); // A left-justified number <42        >

        // A right-justified number
        output = String.format("A right-justified number <%10d>", 42);
        System.out.println(output); // A right-justified number <        42>

        // Octal numbers
        output = String.format("An octal number %o", 100);
        System.out.println(output);// An octal number 144
        output = String.format("An octal number %#o", 100);
        System.out.println(output);// An octal number 0144

        // Hexadecimal numbers
        output = String.format("An hex number %x", 100);
        System.out.println(output); // An hex number 64
        output = String.format("An hex number %#x", 100);
        System.out.println(output); // An hex number 0x64

        // Multiple String arguments of multiple types
        output = String.format("The %1s has %2d moons", "Saturn", 53);
        System.out.println(output); // The Saturn has 53 moons

        // Specify a width
        output = String.format("Fun with <%10s>", "Java");
        System.out.println(output); //Fun with <      Java>

        // Specify a left justification with width
        output = String.format("Fun with <%-10s>", "Java");
        System.out.println(output); // Fun with <Java      >

        // Truncate the maximum number of characters
        output = String.format("Fun with <%.1s>", "Java");
        System.out.println(output); // Fun with <J>
    }

```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://hanfak.gitbook.io/workspace/languages/java/intermediate/string-class.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.