bool true or false and negative return [closed]

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what is the deference between returning a bool (true or false) and returning negative value

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One is binary (either success or failure) The other has discrete values that you can use for error codes. What I do is typically negative values for errors, 0 for success and positive values for warnings.

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It depends on what you are using the return value for.

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A boolean value is usually used when to describe the success or the failure of a process.

Something either "succeeded" (return true) or "failed" (return false).

Some functions (juste like socket()) return a "socket descriptor" which is a positive value. In this case, one way to report that something went wrong is to return an out-of-valid-range value, thus a negative value.

However, keep in mind this is not an absolute truth. One developer might decide to return a positive value for error, and to return 0 for a success. (Just like program exit statuses).

The only way to know what a return value means, is to read the documentation.

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Sometimes you want a method to return true/false based on whether the method executed some code successfully.

However, you might want more detail on why a method failed, but you can't throw an exception (e.g., the language doesn't have exceptions). In this case, you can return an integer value as a sort of error code.

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One you are returning a value of a type which can have 2 possible outputs.

The other you are returning a value of a type which can have many more possible outputs.

By the way, in most programming languages 0 is considered false and everything else is considered true. I get the idea that you think that any negative would be considered false in most languages.

You may want to return a number of different negative numbers for example for different error codes. Or you may simply have a pass/fail only criteria. And you could use a boolean or integer return type depending on which scenario you have.

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• Use boolean return value when your method returns only yes/no.
• Use numbers when you need to indicate something else besides just successful completions.

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If you need a bool result, return a bool(the truck) if you need an integer, return an integer(the apple). For instance, in javascript you can do

var ret = 0;
if (ret){//is ret true?
  alert('Never gets here');
}

if (!ret){//is ret false?
  alert('I will popup');
}

but if you really need to test for a boolean value you MUST do:

var ret = 0;
if (ret === true){//if it is true AND boolean
  alert('Never gets here');
}

var ret = false;
if (ret === false){//if it is false AND boolean
  alert('I will popup');
}

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If you want more than two return codes (true/false) then you will have to return an integer. In C++ there's a typedef of BOOL to int meaning that you can use BOOL as your return type, and TRUE and FALSE for return values, and -1 for an error if you'd like. The typedefs of BOOL, TRUE, and FALSE just serve to improve the readability of your code, but it's just returning an int.

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you may prefer to use an "out" param, for example:

public bool MyFunction(object input, out int status) {...}

so you can have true or false as they success/fail of the function, and a staus variable for any other information about what happened set as well.