How To Fix An Illegal Start Of Expression In Java

1
3IPERTI
EX PERTú C LIE NTS HOM IT V OR KS
How To Fix An Illegal Start Of Expression In Java
HOW TO FIX AN ILLEGAL START OF EXPRESSION
IN JAVA
How To Fix An IIIegaI Start Of E x pres sion In
Cava
Important Thing to Enow for Improving Your
Diversity Recruiting Strategy
I nbound Recruiting What is it And Hov/to Get
You Started
3ava Messenger 2.0 Why the interest from
3ib and containerizing What all top 3ava
Developers know
Being a java developer, you must encounter
numberless bugs and errors on daily basis.
Whether you are a beginner or experienced
software engineers errors are inevitable but over
fime you can get experienced
ARC HIV E S
enough to be able to correct them efficiently.
One such very commonly occurring error is
"Illegal start of expression Java error".
o Jan u ary 2O2ï
f
uecember 2020

• Table of Contenta -'
• 1. \/hat is "illegal start of expression java
  error?
• 2. 1. Use of Access Modifiers with local
  variables
• 2. Method Inside of Another Method
• 8. Class Inside a Method Must Not Have Modifier
• 4.Nested Methods
• 5. Missing out the Curly ()" Braces
• ó. String or Character Without Double Quotes "-"
• Conclusion

o November 2O2O

• Oc rob er 2020

S ep hember 2O2 O
o Au_at_usL2O2O

• J u Iy 2O2O

o June2020
What is illegaI start of expression java error"?
may2020
The illegal start of expression java error is a
dynamic error which means you would encounter it
at compile time with "javac" statement (Java
compiler). This error is thrown when the compiler
detects any statement that does not abide by the
rules or syntax of the Java language. There are
numerous scenarios where you can get an illegal
start of expression error. Missing a semicolon at
the end of The line or an omitting an opening or
closing brackets are some of the most common
reasons but it can be easily fixed with sligM
corr tions and can save you a lot of time in
debugging.
o Aprt2020
o r4 arc h 2O2O
re b r uary 2020
Following are some most common scenarios where
you would face an illegal start of expression Java
error along with the method to fix them,
CA1 EGOkIE S
1. Use of Access Modifiers with local variables
o A r I ic les
Variables that are declared inside a method are
called local variables. Their functionality is
exactly like any
other variable but they have very limited scope
just within the specific block that is why they
cannot be accessed from anywhere else in the code
except the method in which they were declared.
Pre ss k elea se
o un ca tegori zed
Access modifierpublic, private, or protected)
can be used with a simple variable but it is not
allowed to be used with local variables inside
the method as its accessibility is defined by its
method scope.
See the code snippet below,
COmRCTFOLLOt'
1 .
pub Ï ic c1a s s c1a s si
f P B in
4.
public imt localUar 5
Here the public access modifier is used with a
local variable 0ocalVar). This is the output you
will see on the terminal screen
Subscribe to neastetler now!
2
Your emat address.
It reports 1 error that simply points at the
wrong pbcement of access modifier. The sokitân is
to either more the decJ ation of the kcal
variable outside the method (it will not be a
bcal v izéde after that) or simply donot use an
access modifzr with local variables.
2. Method Inside of Another Method
H i re the most sough t-after contingeni
software engineers on-dema nd. and crea te Ihe
perfect blend tor your distri buts https/t
.co/qwXjww Ez8R
Unlike some other programrring lwguages. Java
doos notalkws defining a method inside anotha
method. Attempting to do that would throw the
Illegal start of expression errw.
BeÏow is the demmstrafion ofthe code
1. 2. 5.
public class clasnA ( public static void
main(String args) ( int localVar fi public
void anotherMethod()( System.out.print1n(it is a
metEod inside a œetEod.)
uiversi ry recruiLment strategy best practices
for aracing. engaging assessi ng. a nd hi
ring diverse aien a ari. https.it.co/loesukj7so
V
This wxuld be the output of the code,
1 n bOu nd ttec ru iting is of feri ng the
potential employees w hat Ihey see k in a comp a
ny. lts a com binaiio n of employer https/t
.co/ hDiqu xeOeN '
_at_XPERTI ï
LSTESTPOSTS
lt is a restriction n 3ava so you just have to
avoid using a method insee a method to write a
successfully running code. The best practiœ
would In' to d cbre another method outside the
main methltI and call it in the main as per your
requirern nts.
How To Fix An lllegal Starl ΠExpression In
3. Class Inside a Method Must Not Have Modifier
Important Thing to Know for Improving Your
Diversity Recruiling SFategy
3ava alows its clevelopers to write a class
within a methltI, this is legal arid hence would
not raise my error at cmpatân time. That cbss
will be a local type, simibr to local wizédes
arid the scope of that inner cbss wit also be
restrled just within the rrethod. Howmrer, an
inner class must not begn with access modifzrs
as modifiers are not to be used insée the method.
In the code snippet below, the class "mammals" is
defned inside the main methltI which is inside
the cbss called animab. Using the public ness
modifier with the mammals cbss will generate an
illegal Stat Of Oxgr9SSiOLi jdva r0r.
Inbound Recruiling What is it? And How to Gel
You Starfed?
1. 2. 3.
public class Aninals ( public static final void
main(String args)( public class mammals (
java Messenger 2.0 Why Iheinterest from
s . I The output will öe as follows,
This error can be fixed just by not using the
acœss modifier with the inner class myou can
define a cbss inside a cbss but outside ofa
method md instanfiaông that inner Öass inside the
method.
CATEGOæES
BeÏow is the corrected version of code as well,
1. 2. 3. 4.
class Animals (
o Aftctes
// inside class private class flamals (
6.
Systœ.out.println(This is an inner class)
P re ss Release
10. 11. 12. 13. 1. 15. 16. 17. 18.
// Accessing the inside c1ass mar the nethod
wtthin
o tu nca tegori red
Mammals inside nez Wamals()
)
)
public cla ss Ny_c las s (
3
19. // Instantiating the outer class
20. Animals classA new Animals()
21. // Accessing the disp1ay_Inner() method.
22. c1assA.disp1ay_Inner()
23. 2n. i )
Now you will get the correct output.
4.Nested Methods
Sorry recent programming bnguages, lke Python,
supports nested methltIs but Java doos notalkwto
make a method insicle another method. You will
encounter the illegal start of expressim java
errw if you by to create nested methods. Below
mentioned is a small cocle that aft npts to
declare a method called cal5um inside the method
called outputsum.
1. 2. 3. 4.
public class classA ( public void outputSm(int
numl, int num2) ( 5ystem.out.print1n("Ca1cu1ate
Result cal5um(x, y)) public int calsm ( int
numA, int num2) (
And here is the outpuL
The 3ava compiler has reported five compilatân
errors Other 4 unexpected azors w due to the not
cause. In this code, the first "illegal start of
expression errw is the root cause. It is very
much passible that a single error can cause
multiple further errors during compile time. Same
is the case here' We can easily solve all the
errors byjust avoiding the nesting of methltIs.
The Lest tice, in this case, would be to more
the caisum0 method out of the outputsumg method
and just call it n the method to get the
results. See the correctëd œde beÏow,
1. 2. 3.
public class classA ( public void outputSm(int
numl, int num2) ( 5ystem.out.print1n("Ca1cu1ation
Result ca1Sum(x, y))
5.
public int calsua ( int nm1, int num2) (
5. Missing out the Curly "() Braces
SÑpping a cudy braœ in any method can result in w
ilÏegal stwt of apression java error. Accxding
to the syntax of3ava programming every blöck
orcbss defnition must start and end with curly
des.lfyou skip any curly traces, the compiler
will not be able to idϙfy the starling or ending
point ofa bÏock which will result in an erron
Developers oftën make If\is mistake because there
c' mult_at_le bbclcs and methods nested together
which results in forgetting clasing w opened
curly brackeL lDEs usually prove to be helpful
in this case by dîfferentîatîng the brackets by
assignirig euh pair a differœt colour and even
identify ifyou have forgottën to close a bracket
but sometirres it still gets missed md result in
an illegal Star Of Oxgr9SSiOLi jdva œr0r. In the
folÏowing code snippeL consister this cbss called
Calculator, a method callœl cal5um perform
addition oftwo numbers md stores the result in
the variable total wNch is then printœl on the
screen. The code is fne but it is just missing
a Öosirig curly ket for caŒum method which wei
result in multiple errors.
1. 2.
public class Calculator( public static void
cal5um(int x, int y) (
4
4. total x y
5. Systen. out. print ln(5un " tntal)
7. public static void main(String args)(
8. int nual 3
9. int nua2 2
10. calcsum(num1,num2)
11.
12. )
Pofiowin9 errors will bethrown n screen.
Calculator.javal2 error illegal start oC
erpressioe public int calcSum(int x iut y)(
3error
The root cause ali these illegzJ starts of
expressÓn java error Ó just the missing
Óosirig ket at calsum \dfzle writirig your code
missing a sirigle curly bracket co tzce up a lot
of brn in debugging especially if you are a
beginner so always iookout for iL
6. String or Character Without Double Quotes "-"
3ust like missing a curly ket inifializirig sbing
variables without using cbuble quotes is a comma
mistalce made by many beginna Java developers.
They tend to forget the double quotes and bter
get bombarded with multiple errcs at the run
time including the illegal stat of apc'ssion
errors. If you forget to encbse sags in the
prcper quotes, the Dava compiler will consider
them as variable names. It may result in a
cannot fnd symbol error if the variad e is
riot declared but if you miss the
double-quotations around a string that is not a
valid 3ava wizéde name, it will be reported as
the legal star of apression Java error. The
compile real the Strng wizéde as a sequence of
characters. The chaacters can be alphabets.
numbers or special character every symbol key on
yourkeybaard be a part ofa string. The double
quotes are us I to kx'p them intact and when you
miss a double quote, the cmper can not identify
where this series of characters is ending, it
considers mother quotation anywhere later in the
code as closing quotes arid all that cltIe in
betwea as a sbing causing the error. Consider
this code snippet below the missing quotation
marM around the values of the peraA witf?n if
condifions will generate errors at the run time.
1. 2. 3. 4.
public class Operator( public static void
main(String args)( int numl 10 int num2 8
6. 7. 8.
Scanner scan new Scanner(System.in) tEe
operation to perform(0R)") String operator
scan.nextLine()
10. 1l. 12. 13. 1. 15. 16. 17. 18. 19. 20. 21. 2z
.
output numl num2
)
else if(operator -) output numl - num2
)
else Systea.out.prin1n(Invalid Operator)
Systm.out.prin1n(Result " output)
)
Strng values rixist be always enclosed in double
quotation marM to avoid the error similar to what
this code would return,
Concl usion
In a nutshell, to fix an ilKQal start nf
expression error, look for mistakes t fore the
line mentioned in the error message for missing
brackets, curly Yes w semicoltxis Recheck
the syntax as well. Always kok for the root
cause of the error md always recornpile every
fix you fix a bup tD check as it could be the
rOOt cause Of all Orrms. See Also ava Feature
Spoflight SeaM Classes
5
Such run-time errors are designed t0 assist
developers, if y0u have the required knowledge of
the syntax the rules and restrictions in java
programming and the good programming skills than
you can easily minimize the frequency ol this
error in y0ur code and in case if it Occurs you
would be able t0 quickly
Shaharyar Lalani
RELATED POSTS
Important Thing to Know for Inbound Recruiting \dhat is it 3ava Iles senger 2.0 \dhy the
Improving Your Diversit y Recruiting Strategy And How to Get You Started interest from Flicrosoft
WRITE A COMMENT
Save my name. emaI. and website in this bngtvser
for Ifie next time I cltnrnenL
" " "' "