Java Programming Language
Java Logic Statement Syntax Exercises #1
These exercises are designed to evaluate your knowledge, comprehension, application and analysis of the Java logic statement syntax. It is expected that you should be able to correctly answer all or nearly all of the questions and problems presented. You should do these exercises by yourself.
1. Lookup Unicode values at the http://charts.unicode.org/Web.html website.
|
Character |
Unicode Value |
|
p |
|
|
$03C0 |
|
|
$056D |
|
|
? |
2. Identify valid and invalid comments and why not valid.
|
Valid or Invalid |
Why not valid |
|
|
/* is this a valid comment? */ |
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// is this a valid comment? |
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//* is this a valid comment? |
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*/ is this a valid comment? /* |
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|
// is this a valid comment? |
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/** is this a valid comment? **/ |
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/* is this a valid comment */ |
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// is this a valid comment? // |
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// is this a valid comment? */ |
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/** is this a valid comment? */ |
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|
/* is this a valid comment? // |
3. Identify valid and invalid identifiers and why not valid.
|
Valid or Invalid |
Why not valid |
|
|
int |
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|
myInt |
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|
3cpo |
||
|
$hex |
||
|
period.ending |
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|
r2d2 |
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|
uncle$scrooge |
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|
DumbVarIABle |
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|
dollars$ |
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|
percent%sign |
4. Identify the values into the Java type that it most accurately represents. Take note of the format of the variable values and their range is relation to the Java definitions of types given in the lecture material to make your decision.
|
Value |
Type |
|
123086 |
|
|
True |
|
|
0 |
|
|
0xF0001320DC657AA9 |
|
|
"Hello World" |
|
|
10000000 |
|
|
-543287.12032222 |
|
|
-436 |
|
|
‘Z’ |
|
|
255 |
|
|
5,000,000,000 |
|
|
0377 |
|
|
‘?’ |
|
|
0x0FED1200 |
|
|
False |
|
|
-3,000,000,000 |
|
|
"Java" |
|
|
255L |
|
|
.0001D |
|
|
0xffL |
|
|
4523.346F |
5. Identify valid and invalid literals and their type and why not valid.
|
Type |
Valid or Invalid |
Why not valid |
|
|
+123 |
|||
|
"Hello there" |
|||
|
238 |
|||
|
-4356 |
|||
|
65535 |
|||
|
-32768 |
|||
|
3.14F |
|||
|
'c' |
|||
|
-0.000023 |
|||
|
+6.0 |
|||
|
'why me?' |
|||
|
"z" |
|||
|
true |
|||
|
off |
|||
|
FALSE |
|||
|
null |
|||
|
453,645,786,864 |
|||
|
\0000 |
|||
|
017 |
|||
|
0xffL |
|||
|
3.14159D |
6. Given the following variable declarations, convert or cast the variable into the specified type and fill in the resulting type and value column. Incorporate any automatic promotion to int that is done. If the conversion or casting is invalid then indicate that is so by stating why.
|
Given |
Convert or Cast to |
Result Type & Value |
Why Invalid |
|
int a = 128; |
byte |
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|
short s = 4096; |
int |
||
|
int a = 112; |
int |
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|
char c = 'A'; |
byte |
||
|
boolean b = true; |
int |
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|
short s = -23456; |
double |
||
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int a = 127; |
byte |
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|
byte b = -128; |
long |
||
|
int a = 1,232,598 |
float |
||
|
float f = -3.14 |
boolean |
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|
char c '/u03c0' |
short |
||
|
double d = 0.0001 |
long |
||
|
char c = '2' |
int |
||
|
float f = -542.232 |
double |
||
|
long a = -34 |
double |
||
|
short s = 0xFF00 |
char |
||
|
long a = -1024 |
short |
||
|
float f = 1.1 |
byte |
||
|
byte b = 13; |
Short |