while-loop

When do we use loop and a half? Also, should someone briefly elaborate how to write its code? You use loop-and-a-half to avoid repeating code from outside the loop to the inside. Example: read a; while a != b do stuff; read a; end becomes while true do read a if a == b then break stuff; end Now I only have the read in one place. As an aside, I'd like to add that the scope of the variable (assuming a is a local variable in this idiom) is minimized as compared to the alternative case, where a is still in scope even after the while loop terminates. Minimizing the scope of local variables is

I am not sure what the problem is but I keep receiving this error when I try to use a while statement in my code. Invalid token 'while' in class, struct, or interface member declaration I want to use a while loop to have something continuously update while a statement is true. The rest of my code is rather long but whenever I type in the syntax: while(a<b) { //do whatever i want it to do here } It gives me that compiler error right off the bat. Not quite sure what the problem is. I am doing this in a C# windows application under the Form1.cs file with all the other event handlers (for buttons

I'm tackling a project that requires me to use JavaScript with an API method call. I'm a Java programmer who has never done web development before so I'm having some trouble with it. This API method is asynchronous and it's in a while loop. If it returns an empty array, the while loop finishes. Otherwise, it loops. Code: var done = true; do { async_api_call( "method.name", { // Do stuff. }, function(result) { if(result.error()) { console.error(result.error()); } else { // Sets the boolean to true if the returned array is empty, or false otherwise. done = (result.data().length === 0) ? true :

I wrote a while loop in a function, but don't know how to stop it. When it doesn't meet its final condition, the loop just go for ever. How can I stop it? def determine_period(universe_array): period=0 tmp=universe_array while True: tmp=apply_rules(tmp)#aplly_rules is a another function period+=1 if numpy.array_equal(tmp,universe_array) is True: break #i want the loop to stop and return 0 if the #period is bigger than 12 if period>12: #i wrote this line to stop it..but seems it #doesnt work....help.. return 0 else: return period just indent your code correctly: def determine_period(universe

I usually loop through lines in a file using the following code: open my $fh, '<', $file or die "Could not open file $file for reading: $!\n"; while ( my $line = <$fh> ) { ... } However, in answering another question , Evan Carroll edited my answer, changing my while statement to: while ( defined( my $line = <$fh> ) ) { ... } His rationale was that if you have a line that's 0 (it'd have to be the last line, else it would have a carriage return) then your while would exit prematurely if you used my statement ( $line would be set to "0" , and the return value from the assignment would thus also

I am trying to use json_encode() in a while loop while getting database results. Here is my code: <? $database = sqlite_open("thenew.db", 0999, $error); if(!$database) die($error); $query = "SELECT * FROM users"; $results = sqlite_query($database, $query); if(!$results) die("Canot execute query"); while($row = sqlite_fetch_array($results)) { $data = $row['uid'] . " " . $row['username'] . " " . $row['xPos'] . " " . $row['yPos']; } echo json_encode(array("response"=>$data)); sqlite_close($database); ?> The output of this is {"response":"lastUserID lastUser lastXPos lastYPos"} I want it to be...

I tried the following code different ways, like by taking out the while or the if, but when I put both together (if and while), I always get the error at the end... undefine numero set serveroutput on accept numero prompt 'Type # between 100 and 999: ' declare i number:=1; a char(25); b char(1); c varchar2(10); d number; begin c := &numero; d := length(c); b := substr(c, i, 1); while i <= d loop if b = '1' then a:= a||'one '; end if; i := i+1; end loop; dbms_output.put_line('The number is '||a); end; / ERROR: ORA-06502: PL/SQL: numeric or value error: character string buffer too small ORA