StringBuilder
In this chapter you will learn:
- What is the difference between StringBuilder and StringBuffer
- How to StringBuilder's Constructors to create StringBuilder
- How to create StringBuilder with initial String value
StringBuilder vs StringBuffer
StringBuilder
is identical to StringBuffer except it is not synchronized.
StringBuilder is not thread-safe.
StringBuilder is faster than StringBuffer.
StringBuilder creation
We can create StringBuilder with the following four constructors.
StringBuilder()
Creates a string builder and an initial capacity of 16 characters.StringBuilder(CharSequence seq)
Creates a string builder from the specified CharSequence.StringBuilder(int capacity)
Creates a string builder with no characters in it and an initial capacity specified by the capacity argument.StringBuilder(String str)
Creates a string builder initialized to the contents of the specified string.
The following code creates a StringBuilder with initial capacity set to 20.
public class Main {
public static void main(String[] argv) {
StringBuilder sb = new StringBuilder(20);
sb.append("java2s.com");
//from j av a 2s . c o m
System.out.println(sb.capacity());
}
}
The output:
Create StringBuilder with initial String value
Another way to create StringBuilder is to use String value.
public class Main {
public static void main(String[] args) {
StringBuilder lipsum = new StringBuilder("Lorem ipsum dolor sit amet.");
System.out.println("lipsum = " + lipsum.toString());
//from j a va2 s . co m
lipsum.delete(0, 8);
System.out.println("lipsum = " + lipsum.toString());
lipsum.deleteCharAt(lipsum.length() - 1);
System.out.println("lipsum = " + lipsum.toString());
}
}
The output:
Next chapter...
What you will learn in the next chapter:
- How to append data to the end of a StringBuilder
- How to chain append methods together
- How to insert data to the middle of a StringBuilder
- Combine append and insert methods
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