Core java interview Questions You'll Most Likely Be Asked (Second Edition)

Write a code sample that reverses a String without using a
loop.
Answer:
There are several ways that you can reverse a String without
using a loop. One of the ways is to use the reverse method on
the StringBuilder class. The following code demonstrates this:
StringBuilder sBuilder = new StringBuilder(“Core Java”);
sBuilder.reverse();
System.out.println(sBuilder);
This code creates a StringBuilder instance with the String Core
Java and then invokes the reverse() method on it.
So, this code prints the following output:
avaJ eroC
The StringBuffer class also has a method called reverse()
which can be used to reverse a String.
Write a code sample that demonstrates how you can
convert a String to uppercase.
Answer:

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140.
a.
b.
c.
The String class has a method called toUpperCase(). This can
be used to convert a String to uppercase. The following code
demonstrates this:
String myStr = “Hello World”;
myStr = myStr.toUpperCase();
System.out.println(myStr);
This code creates a String called myStr with the value Hello
World. It invokes the toUpperCase() method on this String
object. So, this code prints the following output:
HELLO WORLD
Explain how you can convert an Integer to a String.
Answer:
There are several ways in which you can convert an Integer to a
String. These are as follows:
Directly enclosing the Integer in quotes: You can enclose the
number in quotes and assign to a String variable as follows:
String strNum = “10”;
Using String.valueOf: The String class has a valueOf
method. You can use this to convert an Integer to a String as
shown below:
String strNum = String.valueOf(10);
Using the Integer.toString method: The Integer class
has a toString method. This can also be used to convert
an Integer to a String as shown below:

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String numStr2 = new Integer(10).toString();

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