Truncating float numbers while displaying in Label field

o6a6r9v1p

i have to display float number with 2 digits after decimal point(truncate).

I have used
Label_Value->setText( QString::number(value, 'f', 2));

it is rounding a larger value while displaying the value.

Then i used parseFloat()

value= parseFloat(value).toFixed(2);
Label_Value->setText( QString::number(value, 'f', 2));

This is giving error message

'parseFloat' was not declared in this scope.

Searched in the net. didnot get any idea.
What is to added/declared to use parseFloat().

Thanks.

jsulm

@o6a6r9v1p said in Truncating float numbers while displaying in Label field:

parseFloat

What is parseFloat?

Toniy

If you need floating value with certain precision without ceiling, try to get string longer by one symbol (three in your case) and remove all symbols that after second fractional digit:

// Let's consider three cases:
// 1. value == 2.65796541324 (longer than two fractional symbols);
// 2. value == 2.6 (shorter);
// 3. value == 2 (integer).
QString str(QString::number(value, 'f', 3));  // 1. str == "2.658"; 2. str == "2.600"; 3. str == "2.000"
str.chop(str.length() - (str.indexOf('.') + 3)); // 1. str == "2.65"; 2. str == "2.60"; 3. str == "2.00"
Label_Value->setText(str);

VRonin

parseFloat is Javascript, not C+++

Label_Value->setText( QString::number(std::trunc(value*100.0)/100.0, 'f', 2)); will do the trick (remember to add #include <cmath>).

o6a6r9v1p

@VRonin

I am mistaken about parseFloat, as you pointed out.
modified code as you told, it is working now.

Thank you.

o6a6r9v1p

@Toniy
Thank you,