javascriptlambdafunctional-programminginvocation

Uncaught TypeError: Illegal invocation in JavaScript

I'm creating a lambda function that executes a second function with a concrete params. This code works in Firefox but not in Chrome, its inspector shows a weird error, Uncaught TypeError: Illegal invocation. What's wrong with my code?

var make = function(callback,params){
    callback(params);
}

make(console.log,'it will be accepted!');
Solution

  • The console's log function expects this to refer to the console (internally). Consider this code which replicates your problem:

    var x = {};
x.func = function(){
    if(this !== x){
        throw new TypeError('Illegal invocation');
    }
    console.log('Hi!');
};
// Works!
x.func();

var y = x.func;

// Throws error
y();

    Here is a (silly) example that will work, since it binds this to console in your make function:

    var make = function(callback,params){
    callback.call(console, params);
}

make(console.log,'it will be accepted!');

    This will also work

    var make = function(callback,params){
    callback(params);
}

make(console.log.bind(console),'it will be accepted!');