BASIC ELEMENTS OF JAVA - Java Programming: From Problem Analysis to Program Design - page 47

This expression evaluates as follows:
"The sum = " + (12 + 16)
= "The sum = " + 38
= "The sum = 38"
Next, consider the expression:
12 + 26 + " is the sum"
This expression evaluates as follows:
12 + 26 + " is the sum"
= (12 + 26) + " is the sum"
= 38 + " is the sum"
= "38 is the sum"
Now consider the expression:
"The sum of " + 12 + " and " + 26 + " = " + (12 + 26)
Notice the parentheses around 12 + 26 . This expression evaluates as follows:
"The sum of " + 12 + " and " + 26 + " = " + (12 + 26)

2

= "The sum of 12" + " and " + 26 + " = " + (12 + 26)

= "The sum of 12 and " + 26 + " = " + (12 + 26)

= "The sum of 12 and 26" + " = " + (12 + 26)

= "The sum of 12 and 26 = " + (12 + 26)

= "The sum of 12 and 26 = " + 38

= "The sum of 12 and 26 = 38"

The following Java program shows the effect of the preceding statements:
// This program illustrates how the String concatenation works.

public class Example2_10
{

public static void main(String[] args)
{

System.out.println("The sum = " + 12 + 26);

System.out.println("The sum = " + (12 + 26));

System.out.println(12 + 26 + " is the sum");

System.out.println("The sum of " + 12 + " and " + 26
+ " = " + (12 + 26));

}

}