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Basic syntax errors in Java are explained.

Some errors are caused by violations of the syntax of Java. Although they are easy to understand, there is no easy way to find the exact causeof such errors except by checking the code around the location of the error character by character looking for the syntax error.


The syntax of Java is very specific about the required punctuation. This error occurs, for example, if you forget a semicolonat the end of a statement or don't balance parentheses:

if (i > j        // Error, unbalanced parentheses   max = i        // Error, missing semicolonelse   max = j;

Unfortunately, this syntax error is not necessarily caught precisely at the point of the mistake so you must carefully check the preceding characters inthe line or even in a previous line in order to find the problem.

Syntax error, insert ") Statement" to complete IfStatement
Syntax error, insert ";" to complete Statement
Eclipse is more informative as to the precise syntax error encountered.

unclosed string literal

String literals must be enclosed in quotation marks. A literal is a source-code representation of a value; most literals are of primitive types like int or char , but there are also literals of type String and the literal null of any reference type. This error occurs if you fail to terminate the literal with quotation marks. Fortunately, the syntax of Javarequires that a string literal appear entirely on one line so the error message appears on the same line as the mistake. If you need a string literal that islonger than a single line, create two or more literals and concatenate them with + :

String longString =   "This is first half of a long string " +  "and this is the second half.";

Eclipse: String literal is not properly closed by a double-quote In Eclipse you can write a string literal of arbitrary length and the environment will break the string and insert the + automatically.

illegal start of expression

Most programming constructs are either statements or expressions. This error occurs when an expression is expected but not found. In Java, an assignment statement is considered to be an expression which returns a value , so errors concerning expressions also apply to assignment statements. The value of an assignment statement considered as an expressionis the value of the expression on the right-hand side that is assigned to the variable on the left-hand side. Examples:

  • An extra right parenthesis after the condition of an if -statement: if (i > j) )        // Error, extra parenthesis   max = i; Eclipse: Syntax error on token ")", delete this token The syntax of a programming language is defined in terms of tokens consisting of one or more characters. Identifiers and reserved keywords are tokens as are singlecharacters like + and sequences of characters like != . Eclipse diagnoses this as a simple syntax error and does not mention expressions.
  • Forgetting the right-hand side of an assignment statement: max = ;            // Error, missing right-hand side Eclipse: Syntax error on token "=", Expression expected after this token

Questions & Answers

Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
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s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
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what's the easiest and fastest way to the synthesize AgNP?
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types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
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preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
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I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
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Source:  OpenStax, Compile and runtime errors in java. OpenStax CNX. Dec 28, 2009 Download for free at http://cnx.org/content/col10913/1.2
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