The isdefined()
is an inbuilt function in julia which is used to test whether the specified global variable or object field is defined or not. The passed parameters can be a module and a symbol or a composite object and field name (as a symbol) or index.
Syntax:
isdefined(m::Module, s::Symbol)
or
isdefined(object, s::Symbol)
or
isdefined(object, index::Int)Parameters:
- m::Module: Specified module.
- s::Symbol: Specified symbol.
- object: Specified composite object.
- index::Int: Specified index.
Returns: It returns true for the defined specified global variable or object field else returns false.
Example:
# Julia program to illustrate # the use of isdefined() method # Getting true for the defined # specified global variable or # object field else returns false. println(isdefined(Base, : sum ))
println(isdefined(Base, :num)) println(isdefined(Base, :NonExistentMethod)) # Initialising a composite type value with # Floor division operator a = 2 / / 3 ;
println(isdefined(a, 1 ))
println(isdefined(a, 2 ))
println(isdefined(a, :num)) println(isdefined(a, :numerator)) |
Output:
true true false true true true false
@isdefined()
The @isdefined()
is an inbuilt function in julia which is used to tests whether the specified variable s is defined in the current scope or not.
Syntax:
@isdefined sParameters:
- s: Specified variable.
Returns: It returns true if the specified variable s is defined in the current scope else returns false.
Example:
# Julia program to illustrate # the use of @isdefined() method # Getting true if the specified variable # s is defined in the current scope # else returns false. function f() println(@isdefined x)
x = 10
println(@isdefined x)
end
f (generic function with 1 method)
println(f()) |
Output: