I am inquiring about data types in Java.
public class Example {
public static void main(String[] args) {
string x = "String variable";
int y = 4;
System.out.println(x);
System.out.println(y);
}
}
Why do I receive an error when I declare a string variable as all lowercase? I can declare integers and other data types all lowercase, but when I declare a string variable I must capitalize the "s" in "string"?
int is a primitive type. String is class. By convention, Java class names start with an uppercase. Primitive types are all lowercase (there are only a few primitive types defined in Java). It's just the way types are named.
int and String are data types. But one is a primitive data type, and the other is a reference data type (e.g. a class or interface). See stackoverflow.com/questions/8790809/… and the Java tutorials.
Because Java is case sensitive and the class is String, not string.
Try Int y = 4;, that won't work either.
Primitive data types like int all start with lowercase, String isn't a primitive data type and thus is capitalized.
integer in java is not a keyword nor a class name.
string neither.
Integer is a class name (wrapper class for integer variable).
int is a keyword (indicates an integer primitive data type).
String is a class name.
Hi: a primitive type is predefined by the language and is named by a reserved keyword. Primitive values do not share state with other primitive values. The String class is not technically a primitive data type, it is included Java API (You can read a little more about it, always useful!). So, the biggest difference between int and String, is only that one is a Java Class, and the other is not.
this is a list of all the primitives in Java (all in lower case):
Numeric primitives: short, int, long, float & double.
Textual primitives: byte and char.
Boolean and null primitives: boolean and null.
For the Java Api Classes, you can check this other post ->
Finally, you can see another difference, I remember this one:
If you want a list of ints, you MUST type the list like this:
List<Integer> myInts = new ArrayList<Integer>();
myInts.add(1);
myInts.add(2);.......
I hope it helps you.
Because it is a predefined class, and it is a common programming style to make the first letter of a class in uppercase only. And all primitive datatypes (like short,char,int,byte,float,double,long,boolean) programming style is to make first letter as small. It is default in java
