var functionVariable = function functionExpressionName() {
functionExpressionName = 1;
console.log(functionExpressionName) // function
};
functionVariable();
If You run this example you can see we can not reassign to functionExpressionName anything. But this is also interesting we can reddeclare functionExpressionName and after this we can assign anything to functionExpressionName
var functionVariable = function functionExpressionName() {
function functionExpressionName() {
}
functionExpressionName = 1;
console.log(functionExpressionName); // 1
};
functionVariable();
If you enable strict mode, the error becomes a bit clearer:
The function name is un-reassignable inside the function, but you can create a new variable with the same name inside the function body. One way of looking at it is that the function name is declared with
const
just outside the function body:This isn't exactly what happens, but it's pretty close.