打印语句中的运算符

Question

Example:

System.out.println("the investment doubled after "+year+" years.");

Can someone please explain why the int variable year is inside quotations and pluses?

Answer 1

Adding some spacing around the operators may make this statement clearer:

System.out.println("the investment doubled after " + year + " years.");

This statement prints the result of a concatination of three strings, achieved by the two + operators:

1. "the investment doubled after "
2. The implicit conversion of the int variable year to a string
3. " years."

Answer 2

It is like this. And + is used for String concatenation. In this year is converted into String from int implicitly.

"the investment doubled after " + year + " years."
 ^-------inside quotes-------^            ^-----^Inside quotes

Answer 3

Here you are using the public void println(String x); method. Which means the integer will concatenated to the string when you append the years to the string, that is the reason we are using the + operator.

Answer 4

Your variable year is not inside quotes, it's actually outside of quotes. It is in between of + sign because you are concatenating it.