Java Reference
In-Depth Information
String s
⇒
Declares the variable
s
of type String.
s = "abc"
⇒
Assigns the value
"abc"
to the variable
s
.
d = Math.random()
⇒
Assigns a random number between 0(inclusive) and 1(exclu-
sive) to the variable
d
.
Returns a positive integer if
s1 > s2
,0if
s1 = s2
,anda
negative integer if
s1<s2
(the string order is lexicographical).
⇒
s1.compareTo(s2)
⇒
Returns
true
when the strings are the same and
false
otherwise.
s1.equals(s2)
if(a > b)
{
...
}⇒
If
a>b
, then the block is executed.
{
...
}
{
...
}⇒
if(a > b)
If
a>b
, then only the first block is executed. Oth-
erwise, only the second block is executed.
else
⇒
True when
a
=
b
.
a==b
a!=b
⇒
True when
a
=
b
.
a>=b
⇒
True when
a
≥
b
.
a<=b
⇒
True when
a
≤
b
.
a>b && c>d
⇒
True when
a>b
and
c>d
.
a>b || c>d
⇒
True when
a>b
or
c>d
.
!(a==b)
⇒
True when the variables
a
and
b
are different.
switch(i)
{
case 4:
...
break; case 5:
...
break;
...
default:
...
If
i=4
, then the statements for the first case are executed. If
i=5
, then the statements
for the second case are executed. If
i
isnotequaltoanyofthecasevalues,thenthe
statements for the default case are executed.
}⇒
⇒
Prints
hello
followed by a new line.
System.out.println("hello")
System.out.print("hello
\
n")
⇒
Prints
hello
followed by a new line.
⇒
System.out.print("hello")
Prints
hello
.
⇒
Scanner keyboard = new Scanner(System.in)
Creates a scanner object.
int i = keyboard.nextInt()
⇒
Reads the next integer from the keyboard into the
variable
i
.
double d = keyboard.nextDouble()
⇒
Reads the next double from the keyboard
into the variable
d
.
String s = keyboard.next()
⇒
Reads the next string from the keyboard into the
variable
s
.
String s = keyboard.nextLine()
⇒
Reads the next line from the keyboard into
the variable
s
.
x = (a>b) ? y : z
⇒
If
a>b
,then
x
becomes equal to
y
. Otherwise,
x
becomes
equals to
z
.
