Java Chapter 7 Questions and Answers with Certified Solutions

Java Chapter 7 Questions and Answers with Certified Solutions What is a string in Java? A sequence of characters enclosed in double quotes. How do you declare a string in Java? By using the `String` class, such as `String text = "Hello";`. Are strings mutable in Java? No, strings in Java are immutable, meaning their values cannot be changed after creation. How do you compare two strings for equality? By using the `.equals()` method, such as `s(str2)`. What is the difference between `==` and `.equals()` when comparing strings? `==` checks if two string references point to the same object, while `.equals()` checks if their values are the same. 2 How do you find the length of a string? By using the `.length()` method, such as `h()`. What happens if you try to modify a string in Java? A new string object is created, as strings are immutable. How do you concatenate two strings? By using the `+` operator or the `.concat()` method. What method converts a string to uppercase? The `.toUpperCase()` method. How do you extract a portion of a string? By using the `.substring()` method. What does the `.charAt()` method do? It returns the character at a specific index in the string. 3 How do you replace characters in a string? By using the `.replace()` method. What method splits a string into an array based on a delimiter? The `.split()` method. How do you check if a string contains a specific sequence of characters? By using the `.contains()` method. What is the purpose of `.trim()` in Java? It removes leading and trailing whitespace