I'm studying higher order functions following the Eloquent JavaScript book. I haven't been able to understand this code, why is "Boolean" passed as noisy first argument?
This is supposed to be function that changes other function, I just don't get how it works!
function noisy(f) {
return function(arg) {
console.log("calling with", arg);
var val = f(arg);
console.log("called with", arg, "- got", val);
return val; };
}
noisy(Boolean)(0);
// → calling with 0
// → called with 0 - got false
noisy
accepts any one-argument function as its argument. It returns a new function that calls that function, but displays messages before and after it calls it.
Boolean
is just an example function that they used. It converts its argument to a boolean datatype.
Boolean is a constructor function for the Boolean type. It could be any function.
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