Java Reference
In-Depth Information
sense for Java to have a number of special syntax features designed to make han‐
dling strings easy. Let's look at some examples of special syntax features for strings
that Java provides.
String literals
As we saw in Chapter 2 , Java allows a sequence of characters to be placed in double
quotes to create a literal string object. Like this:
String pet = "Cat" ;
Without this special syntax, we would have to write acres of horrible code like this:
char [] pullingTeeth = { 'C' , 'a' , 't' };
String pet = new String ( pullingTeeth );
This would get tedious extremely quickly, so it's no surprise that Java, like all
modern programming languages, provides a simple string literal syntax. The string
literals are perfectly sound objects, so code like this is completely legal:
System . out . println ( "Dog" . length ());
This method is defined on Object , and is designed to allow easy conversion of any
object to a string. This makes it easy to print out any object, by using the method
System.out.println() . This method is actually PrintStream::println because
System.out is a static field of type PrintStream . Let's see how this method is
public void println ( Object x ) {
String s = String . valueOf ( x );
synchronized ( this ) {
print ( s );
newLine ();
This creates a new string by using the static method String::valueOf() :
public static String valueOf ( Object obj ) {
return ( obj == null ) ? "null" : obj . toString ();
The static valueOf() method is used instead of toString()
directly, to avoid a NullPointerException in the case where
obj is null .
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