Go Closures

Internal

• Functions

Overview

A closure is an anonymous functions declared within a block - and implicitly, within another function. The function continues to have access to the local variables it had access when it was created for the duration of its life. The function isn't given a copy of this variables, it has direct access to the same variables declared in the scope of the outer function: if the value of the variable changes in the outer function, that is reflected in the inner function. The function together with the non local variables it references is known as a closure.

inClosuresScope := 10

var c = func (i int) {
    inClosuresScope += i
}

s := []int {1, 2, 3, 4, 5}

for _, value := range s {
     c(value);
}

Alternatively, the function literal and invocation can be defined in-line:

inClosuresScope := 10

s := []int {1, 2, 3, 4, 5}

for _, value := range s {
     func (i int) {
         inClosuresScope += i
     }(value);
}

More about closures is available here.