Strings Java

What is the correct way to declare and initialize a String variable in Java?

• String str; str = 'Hello';

• String str = new String('Hello');

• String str = "Hello";

• String str = new String(); str = 'Hello';

How can you concatenate two Strings in Java?

• string1.append(string2)

• string1.concat(string2)

• string1 + string2

• string1.add(string2)

What does the charAt method in Java return?

• The length of the string

• The character at the specified index

• The index of the specified character

• A boolean value

How can you extract a substring from a String in Java?

• string.extract(startIndex, endIndex)

• string.getSubstring(startIndex, endIndex)

• substring.extract(startIndex, endIndex)

• string.substring(startIndex, endIndex)

Which method is used to search for a specific character in a String in Java?

• searchChar()

• findChar()

• locateChar()

• indexOf()

How can you replace a specific character in a String in Java?

• str.replace('a', 'b', 1);

• str.replaceFirst('a', 'b');

• str.replaceAll('a', 'b');

• str = str.replace('a', 'b');

Which class is preferred for manipulating mutable strings in Java?

• String

• StringBuilder

• StringBuffer

• StringWriter

How can you remove leading and trailing whitespaces from a String in Java?

• myString.trim()

• myString.removeSpaces()

• myString.trimWhitespace()

• myString.strip()

String x = "10";

String y = "20";

String z = x + y;

System.out.println(z);

Guess the output.

• 1020

• 10 20

• 30

• "10 20"

What will be the output of below code?

String statement = "Outfit of the day";

System.out.println(statement.Substring(3,6));

• it of

• tfit

• fit

• FIT