call和apply - pod4g/tool GitHub Wiki

function fn1() {
    console.log(1);
}

function fn2() {
    console.log(2);
}

fn1.call(fn2);
fn1.call.call(fn2);
fn1.call.call.call.call.call(fn1);
Function.prototype.call.call(fn1);
Function.prototype.call(fn1);