Answer:
Optional
Explanation:
Variable declaration means when you declaring a variable in the code,whenever you want to use a variable you should declare it or define the variable with come constant.
Example
var name ;
The variable has no value after the statement (technically it has undefined value). Declaring a variable without var keyword is not recommended. An current global variable may accidentally be overwritten.
Example
a=2;
The range of variables declared without var keywords becomes global regardless of where they are declared
