For loop won't end. Don't know why -

-

i'm writing loop project prompts user input number , keeps prompting, continually adding numbers up. when string introduced, loop should stop. i've done while loop, project states must loop also. problem prompt keeps running when 'a = false'. explain javascript's thinking process? want understand why keeps running through loop though condition isn't met. thank you

 var addsequence2 = function() {          var total = 0;         var a;          (; = true; ) {             var input = prompt("your current score " +total+ "\n" + "next number...");              if (!isnan(input)) {                 = true;                 total = +total + +input;             }             else if (isnan(input)) {                 = false;                 document.write("your total " + total);             }         }  };

there difference between a = true , a == true.

your for-loop asking "can set 'a' true?", answer yes, , loop continues.

change condition a == true (thus asking "is value of 'a' true?")

to elaborate, in programming languages, distinguish between assignment ("make 'x' 4") , testing equality ("is 'x' 4?"). convention (at least in languages derive syntax c), use '=' assign/set value, , '==' test.

if i'm understanding specification correctly (no guarantee), happens here condition condenses follows:

  1. is (a = true) true?
  2. complete bracket: set true
  3. is (a) true? (we set true, must be!)

Comments

Post a Comment

Popular posts from this blog

matlab - "Contour not rendered for non-finite ZData" -

-
i'm trying plot frequency characteristic equation using ezplot, matlab gives following warning, "contour not rendered non-finite zdata". have used command plot frequency equations warning , plot display empty , not change axis range well. can please help. appreciated. here's code i'm using. % transfer matrix case-i, thin rotor clear all; clc; ei = 1626; l = 0.15; m = 0.44108; = 2.178*10^-4; i_p = 2.205*10^-5; itr = 0.24; i_pr = 0.479; syms p n; f = [1 l*1i l^2/(2*ei)*1i l^3/(6*ei); 0 1 l/ei -l^2/(2*ei)*1i; 0 0 1 -l*1i; 0 0 0 l]; p = [ 1 0 0 0; 0 1 0 0; 0 -it*p^2+i_p*n*p 1 0; -m*p^2 0 0 1]; p_r = [1 0 0 0; 0 1 0 0; 0 -itr*p^2+i_pr*n*p 1 0; -m*p^2 0 0 1]; = f*p*f*p*f*p*f; b = p_r*f*p*f*p*f; r = a(1,2)/a(1,4); a12_p = 0; a22_p = a(2,2)-r*a(2,4); a32_p = a(3,2)-r*a(3,4); a42_p = a(4,2)-r*a(4,4); ap(2,2) = a22_p; ap(3,2) = a32_p; ap(4,2) = a42_p; ap(4,4) = 1; c = b*ap; m = [c(3,2) c(3,4); c(4,2) c(4,...
Read more

delphi - Indy UDP Read Contents of Adata -

-
i using indy udp server read string of data. however, not know how work adata parameter. can around converting binary using bytetobin function below , convert hex using bintohex1 . feel stupid , works slow. know how can directly results without 2 conversions? thanks!! here codes: procedure tform1.idudpserver1udpread(athread: tidudplistenerthread; const adata: tidbytes; abinding: tidsockethandle); var buf: tidbytes; buffer: string; data_received: string; begin if bytestostring(adata) <> 'hello' begin buffer := hextostring('00'); setlength(buf, length(buffer)); copytidstring(buffer, buf, 0); abinding.sendto(abinding.peerip, abinding.peerport, buf); data_received := bintohex1(bytetobin(adata[1]) + bytetobin(adata[2]) + bytetobin(adata[3]) + bytetobin(adata[4]) + bytetobin(adata[5]) + bytetobin(adata[6]) + bytetobin(adata[7]) + bytetobin(adata[8]) + bytetobin(adata[9]) + bytetobin(adata[10]) + bytetobin(adata[11...
Read more

qt - How to embed QML toolbar and menubar into QMainWindow -

-
i using qwt library plot data. seems not possible embed qwidget qml quick 2 . so, decided create qmainwindow main window , create toolbar , menubar using quick controls . how should embed qml toolbar , menubar qmainwindow ? you should create qml applicationwindow qml menubar , toolbar main.qml applicationwindow { visible: false menubar: menubar { menu { title: "edit" menuitem { text: "cut" } } } toolbar: toolbar { row { anchors.fill: parent toolbutton { iconsource: "1.png" } } } } main.cpp qapplication app(argc, argv); qqmlapplicationengine engine; engine.load(qurl(qstringliteral("qrc:///main.qml"))); then pointer applicationwindow qwindow *qmlwindow = qobject_cast<qwindow*>(engine.rootobjects().at(0)); create window container, using qwidget::createwindowco...
Read more