Java stringbuffer ensureCapacity

ensureCapacity(int minCapacity): ensures that the capacity is at least equal to the specified minimum.

Syntax:

public void ensureCapacity(int minCapacity)

Note:

If current capacity is greater than the argument there will be no change in the current capacity.
If current capacity is less than the argument there will be change in the current capacity using below rule.
```
newcapacity = (oldcapacity*2) + 2
```

Example:

StringBufferEnsureCapacityExample.java

/**
 * This program is used to show the use of ensureCapacity() method.
 * @author w3spoint
 */
class TestStringBuffer{
	StringBuffer sb = new StringBuffer();
 
	/**
	 * This method is used to show the use of ensureCapacity() method.
	 * @author w3spoint
	 */
	public void ensureCapacityTest(){
		//default capacity.
		System.out.println(sb.capacity());
 
		sb.append("Hello ");
		//current capacity 16.
		System.out.println(sb.capacity());
 
		sb.append("www.w3spoint.com");
		//current capacity (16*2)+2=34 i.e (oldcapacity*2)+2.  
		System.out.println(sb.capacity());
 
		sb.ensureCapacity(10);
		//now no change in capacity because 
                //minimum is already set to 34. 
		System.out.println(sb.capacity());  
 
		sb.ensureCapacity(50);
		//now (34*2)+2 = 70 as 50 is greater than 34.
		System.out.println(sb.capacity());
	}
}
 
public class StringBufferEnsureCapacityExample {
	public static void main(String args[]){
		//creating TestStringBuffer object
		TestStringBuffer obj = new TestStringBuffer();
 
		//method call
		obj.ensureCapacityTest();
	}
}

Output:

Download this example.

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