SE450: Horstmann Chapter 1: String concatenation

SE450: String concatenation [34/53]

+ operator concatenates strings:
```
"Hello, " + name
```
If one argument of + is a string, the other is converted into a string:
```
int n = 7;
String greeting = "Hello, " + n;
 // yields "Hello, 7"
```

toString method is applied to objects

Date now = new Date();
String greeting = "Hello, " + now; 
 // concatenates now.toString()
 // yields "Hello, Wed Jan 17 16:57:18 PST 2001"