DancingFighterG
asked on
Question on checking for the size of a float value
Hello, i'm tyring too check if an float value that someone enters is correct and does not exceed a certain range. Right now I'm trying to use E, where represnts the exponent to a power of 10 and digits represents 1 or more juxtaposed numbers. E can be the lower case, "e". There can be no more than 7 digits in any floating points number excluding the exponent (the decimal point does not count as a digit) Exponents are restriced to range of -38 to 38.
This is what I have right now:
else if(out == 3)
{
int exponent_check = 0;
std::istringstream(Lexeme. substr((Le xeme.lengt h())-2 ,Lexeme.length())) >> exponent_check;
if(((exponent_check >= 38) || (exponent_check <= -38)) &&
((Lexeme.find("e") == ((Lexeme.length())-3)) || (Lexeme.find("E") == ((Lexeme.length())-3)) ||
(Lexeme.find("e") == ((Lexeme.length())-4)) || (Lexeme.find("E") == ((Lexeme.length())-4))) && Lexeme.find(".") != 0)
{
cout << "\n*** ERROR - Float Literal exponent is out of range ( -38 < x < 38 )" << endl;
// num_bad_real_constants++;
return 40;
}
I'm trying to check the the length then compare. The number that I am checking is the following:
1.35562127e1
This number should be throwing an error but it doesn't so I need to know what I am doing wrong in the check. Any help with this would be great.
This is what I have right now:
else if(out == 3)
{
int exponent_check = 0;
std::istringstream(Lexeme.
if(((exponent_check >= 38) || (exponent_check <= -38)) &&
((Lexeme.find("e") == ((Lexeme.length())-3)) || (Lexeme.find("E") == ((Lexeme.length())-3)) ||
(Lexeme.find("e") == ((Lexeme.length())-4)) || (Lexeme.find("E") == ((Lexeme.length())-4))) && Lexeme.find(".") != 0)
{
cout << "\n*** ERROR - Float Literal exponent is out of range ( -38 < x < 38 )" << endl;
// num_bad_real_constants++;
return 40;
}
I'm trying to check the the length then compare. The number that I am checking is the following:
1.35562127e1
This number should be throwing an error but it doesn't so I need to know what I am doing wrong in the check. Any help with this would be great.
Hi DancingFighterG,
Perhaps you should have this question in the C++ TA. I can give you a C solution if you want. Alernatively, I can move this question to C++ TA. Since some experts visit both C and C++ TAs, may beyou can wait a while before they see and comment on this.
sunnycoder
Perhaps you should have this question in the C++ TA. I can give you a C solution if you want. Alernatively, I can move this question to C++ TA. Since some experts visit both C and C++ TAs, may beyou can wait a while before they see and comment on this.
sunnycoder
Your exponent is within the range. That's why it is not throwing error.
But, I have got one suggestion for you: Divide your condition statement to different if statements. And don't do the calculation inside a condition statement. Make it as simple as possible. Then it will be easier to debug and understand and errors will be lesser.
-ssnkumar
But, I have got one suggestion for you: Divide your condition statement to different if statements. And don't do the calculation inside a condition statement. Make it as simple as possible. Then it will be easier to debug and understand and errors will be lesser.
-ssnkumar
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ASKER CERTIFIED SOLUTION
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Make some tests with log() function.
Remember to #include "math.h" header file.