Test: Strings - 2 - EmSAT Achieve MCQ

Strings in Java are implemented as objects of the 'String' class, which internally represents them as arrays of characters.

The '==' operator compares the memory addresses of two objects. In this case, 'str1' and 'str2' refer to different string objects, so the result will be false.

The 'concat()' method is used to concatenate two strings in Java. For example, 'str1.concat(str2)' will concatenate 'str2' to the end of 'str1'.

The 'toUpperCase()' method returns a new string with all characters converted to uppercase. However, the original string 'str' remains unchanged. Therefore, the output will be "java".

The 'length()' method is used to determine the length of a string in Java. For example, 'str.length()' will return the number of characters in the string 'str'.

The 'split()' method is used to split a string into an array of substrings based on a delimiter. In this case, the delimiter is "," (comma), so the string will be split into two tokens: "Hello" and "World".

The 'split()' method divides the original string into substrings at the specified delimiter. In this case, the first token is "Hello", which is stored at index 0 of the 'tokens' array.

The 'split()' method divides the original string into substrings at the specified delimiter. In this case, the second token is "World", which is stored at index 1 of the 'tokens' array.

The 'split()' method splits the original string into substrings based on one or more whitespace characters. In this case, the first token is "Hello", which is stored at index 0 of the 'tokens' array.

The 'replace()' method replaces all occurrences of a specified substring with another substring. In this case, "Java" is replaced with "Python", resulting in the string "Python Programming".

The given code reverses the string "CodeChef" character by character and stores the result in the variable 'result'. The output will be "fehCedoC".

The 'substring()' method returns a new string that is a substring of the original string. In this case, the substring from index 7 to 11 (excluding the character at index 12) is "World".

The 'replace()' method replaces all occurrences of a specified substring with another substring. In this case, "l" is replaced with "L", resulting in the string "HeLLo".

The 'substring()' method returns a new string that is a substring of the original string. In this case, the substring from index 1 to 3 (excluding the character at index 4) is "Hell".

The 'substring()' method returns a new string that is a substring of the original string. In this case, the substring from index 0 to 1 (excluding the character at index 2) is "Op", and the substring from index 3 to the end is "AI". The two substrings are concatenated to form the string "OpAI".