ASSERT failure in QList<T>::operator[]: "index out of range"

[jsulm]

@Jerwinprabu @joeQ Or just do

return;

if you do not use the return value...

[Jerwinprabu]

@jsulm @joeQ Thanks for your help. Ya @joeQ given proper sample. I have tried that. Here I have posted the solution now client side that is working fine, one time I want to check from server side. Kindly check, if anything wrong awaiting for your further response

startvaluexy = Client::straightxy;
qDebug() << "start xy value Received from server :" << startvaluexy;
QStringList xy = startvaluexy.split("|");
int xySize = xy.size(); 
qDebug() << "start xy size :" << xySize;

if(xySize > 4){
     x = xy[2];
     y = xy[3];
  }

     QString num1 = x;
     int x = num1.toInt();

     qDebug() << "start x value  :" << x;

     QString num2 = y;
     int y = num2.toInt();

     qDebug() << "start y value :" << y;

    xstart = x;
    ystart = y;

After checking the size will modify this xySize > 4

[jsulm]

@Jerwinprabu said in ASSERT failure in QList<T>::operator[]: "index out of range":

if(xySize > 4){

shouldn't it be

if(xySize >= 4){

?
And if it is not >= 4 what would be the values of x and y? Shouldn't you just skip processing in this case (do return as @joeQ suggested)?

What are you trying to do with this

QString num1 = x;
int x = num1.toInt();

?! Why do you assign an integer to a string and then convert this string to integer again? Same for

QString num2 = y;
int y = num2.toInt();

[Jerwinprabu]

@jsulm from server I will receive the string then I want to convert that string into int. Again I want to convert for sending to server(for map).

[jsulm]

@Jerwinprabu Then why do you convert it back from string to int? x is already int, what's the point to convert from string to int?
Also

QString num1 = x;

is not a conversion to string from int! It will not even compile. If you want to convert int to string then do it like shown here http://doc.qt.io/qt-5/qstring.html#number

[Jerwinprabu]

@jsulm Because I want to take that value to int only xstart, ystart. I want to convert from string to int only. x, y is not int.

QString x;
QString y;

[jsulm]

@Jerwinprabu Again

QString num1 = x;
int x = num1.toInt();

x already contains the integer value! Now you convert it to string then again to int - it will be same as before.

int x = 1;
QString num1 = QString::number(x);
x = num1.toInt();
qDebug() << x;

What do you think the last line will print out?
Shouldn't it be just

QString num1 = QString::number(x);
xstart = x;

?

[jsulm]

@Jerwinprabu Also here you redefine the variable x

QString num1 = x;
int x = num1.toInt();

is there a reason why you're doing this?

[jsulm]

After chatting with @Jerwinprabu I realised that I misunderstood his code: x and y are actually QString not int.

[mrjj]

@jsulm
Well x is a pretty confusing name for a string in most cases.
I was sure also it was int.