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npa · 08-05-2003, 04:34 PM

"i accidently get NullPointerExceptions when checking
what strings equal, how can i avoid it easily?":

Code:

String a = null;
if(a.equals("Hello")){ // oops exception!
}

// this may be solved with:
if(a != null && a.equals("Hello"))

// but you can just do:
if("Hello".equals(a)){ // and avoid checking null at all.

It is good practice to put the constant value on the
left-hand-side so accidents dont occur in other languages
(javascript, c, c++) where they evaluate assignment to
be either true or false and hence a valid expression in
an "if" statement.

08-05-2003, 04:34 PM	#16 (permalink)
npa Code Monkey Join Date: Jul 2003 Location: canada Posts: 82	"i accidently get NullPointerExceptions when checking what strings equal, how can i avoid it easily?": Code: String a = null; if(a.equals("Hello")){ // oops exception! } // this may be solved with: if(a != null && a.equals("Hello")) // but you can just do: if("Hello".equals(a)){ // and avoid checking null at all. It is good practice to put the constant value on the left-hand-side so accidents dont occur in other languages (javascript, c, c++) where they evaluate assignment to be either true or false and hence a valid expression in an "if" statement. __________________ direct entry file specification.