Recently I came across flag variables, but I have no idea what they do.
I am little unsure about when to use a flag variable and how to go about it.
A flag variable, in its simplest form, is a variable you define to have one value until some condition is true, in which case you change the variable's value. Using flag variable(user defined variable, not a predefined) you can control the flow of a function or statement, allowing you to check for certain conditions while your function progresses.
As an example:
// errors is the flag var var errors = 0; for(var i = 0; i < 10; i++) if(i == 6) // your error condition errors++; if(errors) // is the flag "up"? (i.e. > 0) alert("There was a problem!");
A flag is a variable used to have some value until some condition becomes true,then we change it to false and print the output (Initially flag considered as true)
A flag variable is usually given one value,
False. It's used as a Boolean variable where the result toggles between 0 (False) and 1 (True) or as used by the programmer. Some prefer
flag = 0 and change it to
flag = 1 in the program to perform an action.
No matter what language you are using, the concept of flag variables is always the same: a variable that stores a boolean value. A boolean value is one which is always either
false or is either
1 (depending on the language and programmer's personal preference).
Flag variables (also called
boolean variables, or often just
flags) are used to indicate a condition which can only be either of the two boolean values. The value of the variable can toggle depending on events in the program.
var isRaining = false; // It is either raining or not raining. var statusCode = true; // Status codes may be boolean values.
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