![]() The curly brackets define the scope as everything inside the ‘switch’ statement. This means the compiler will interpret this as a jump directly to the label. The reason for this is that ‘case’ statements are only ‘labels’. This is actually not just limited to C++, it happens in other languages as well. The above gives the following error: initialization of ‘newVal’ is skipped by ‘case’ label Let’s start with an example: switch (val) So why can’t you declare variables after a case label in a switch statement? In fact, declaring them close the first use is actually a good practice. This must actually be surprising to most people familiar with C++ programming because C++ allows us to declare variables almost anywhere in the program. If that’s the reason you are here, then read on. Throughout the rest of this chapter, I'll share some other things that you can do with string values.You tried to declare a variable after a ‘case’ statement and it showed an error. So those are a few things to know about strings in Java. The result is a string just like any other. In this code I'm declaring an array of char values and then I'm creating a string using a particular constructor of the string class that receives that array. Because a string is made up of characters, you can start with an array of characters and then create a string from it. Internally though, this is resulting in creating another object when you reset the value. For example, I can declare a string variable and then immediately assign a different value, and the compiler will let you do that and it will work. Java code makes it look like you can do this. Once initialized, their values can't be changed. Another thing to know about strings is that they're immutable. So for example, if I have a string object who's value is hello with an exclamation, that contains an array of char values, six values in an ordered collection. A string refers to an array of character values. Here are some other things to know about strings. Internally, these two bits of code are doing something a little bit different, but functionally for most applications you get the same result. It's once again creating an object and assigning a value but it does it more simply, and this is a special feature of the string class. The second version however is using short-hand. The first example is using classic object construction syntax with the keyword 'new' and then a call to the string constructor. Here are two different ways of declaring a string. As I've mentioned previously, you don't have to import the java.lang package. So, string values are instances of the class. And when the method is called, it displays a message on the console. But after instantiating the object named 'item', I'm setting the value of one of its fields named 'type' and then calling one of its methods. It's not common in actual production applications. This kind of code is typically created for demonstration. And then within the main method, there's code to declare an instance of the same class. In this code, I have a main method which is called automatically when I run the class from the command-line. ![]() You'll see codes sometimes in Java, particularly in command-line applications where the class essentially instantiates itself. This results in a variable where the object it points to is null. In this code, once again I have the data type and the identifier, but then I finish the statement. So this code declares and initializes the value, but you can also declare without initializing. That value has to be a string, and a literal value wrapped in double quotes is always a string in Java. I'm using a version of the constructor method that accepts a single argument or parameter. There are multiple constructor methods in this string class. Then after the equals operator, the assignment operator, the new keyword, and then the constructor method for that class. Then the identifier, the name of the variable. ![]() ![]() In this code, I'm starting with the data type string, that's the name of the class. And when you create an instance of a class it's referred to sometimes as initialization or as instantiation. In Java, a string is an object, and instance of a class.
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