Meaning of + symbol with Strings in Java println statement

Question

I\'m new to Java. What does the below mean?

(addition) + sign in println

System.out.println ("Count is: " + i);

Answer 1

In that context, the + operator is acting as the string concatenation operator. It acts as a different operator in the context of two integral types, where addition will be performed.

Assuming i is an integral type, it'll be converted to a String and then added on to the end of a new string beginning with "Count is: ". That new string is then printed.

ie. If i had the value 0, it'd be the same as:

"Count is: " + "0"

Which would be:

"Count is: 0"

Answer 2

It does exactly what it does outside the println method, id adds to objects:

if the objects are Strings it concatenates them:

"hello" + "world" --> "helloworld"

if the objects are numbers it adds the UNLESS there's a String to the left (or at least a String with higher precedence).

2 + 4 + "hello" --> "6hello"

"hello" + 2 + 4 --> "hello24"

"hello" + (2 + 4) --> "hello6"

if the object is any thing else it will treat them as Strings using the toString() method

Answer 3

+ is string concatenation operator and it is used for conversion of other objects to strings (based upon the implementation of toString() method) and also concatenate two strings.

String str1="Hello";
String str2="World"

String result=str1 + " " + str2;

Answer 4

The + sign in the context of strings is the concatenation operator. It joins two strings together.

E.g.

String str = "hello" + "world";

would result in a String object called str, with a value of "helloworld".

Answer 5

The plus operator has a double meaning. Its a concatination operator as well. As the "Count is:" is of type String the "i" (Integer?) is converted to a String as well.

I haven't read it as I prefer reference books, however some really like the Book Head First Java as it seems to explain concepts.

Answer 6

The + in arithmetic adds 2 numbers together, like this:

2 + 2 = 4

now apply the same thing to a string:

"hello " + "world!" = "hello world!"

now adding strings and variables will do this:

int number = 4;
String string = "what was the number? oh yeah: "+number;
System.out.println(string);

if all goes well you should get "what was the number? oh yeah: 4"

Java took the value of the variable and put it into the string for you, hope this helped!