If statement problem

[purpleblue]

hi,

my code skeleton is like this:

if ( cin.fail() )
{............}
else { bool input_is_good =true; }

if (input_is_good) {.....................}

What I want it to do is: if input doesn't fail, then it will go to else statement, and then input_is_good will be assigned to true. Thus, I can go to the next if statement if input is correct, otherwise don't execute the second id statement. But when I compile the program, it says input_is_good is undeclared (first use this function) But I do declare it in the else statement.

I also try the following way:

if ( cin.fail() )
{............}

else { int input_is_good = '1' ; } //btw do I need to single quote 1??

if (input_is_good) {.....................}

this doesn't work either.

please help me.
thanks

[Mathhead200]

You're defining the variable in a different (inner) scope, and so C++ (the compiler) doesn't know about it anymore after you pass by the closing brace }, (i.e. the end of the block.)

int input_is_good = false; //defined in this scope; use true/false in C++ (not 1/0)

if( cin.fail() ) {
    ...
} else {
    ...
    input_is_good = true; //fine, this block is nested inside so it can still see input_is_false
}

if( input_is_good ) {
    ...
}

That being said, there are better ways to accomplish this. For example, why don't you put the "if input_is_bad" code directly in the else block (my line 6)?

btw do I need to single quote 1?

No. 1 without quotes is an int literal: i.e. 0000 ... 0001 = 1₁₀

'1' with quotes is a char literal: i.e. 0011 0001 = 49₁₀

[Aramil of Elixia]

u only use qoutes in languages like shell and maybe batch