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const obj = { name: 'jiujue', age: 18 }

function print(...args) {
	console.log(this)
	console.log(...args)
}
print.myCall(obj, 1, 2, 3)
Function.prototype.myCall = function(context = window) {
	if (typeof this !== 'function') {
		throw new TypeError('need a function')
	}
	context.fn = this
	const args = [...arguments].slice(1)
	const res = context.fn(...args)
	delete context.fn
	return res
	1
}

Function.prototype.myApply = function(context = window) {
	if (typeof this !== 'function') {
		throw new TypeError('need a function')
	}
	context.fn = this
	if (arguments[1]) {
		let res = context.fn(...arguments[1])
	} else {
		let res = context.fn()
	}

	delete context.fn
	return res
}

const obj = { name: 'jiujue', age: 18 }

function print(...args) {
	console.log(this)
	console.log(...args)
}
let p = print.myBind(obj)
p(1, 2, 3)
Function.prototype.myBind = function(context = window) {
	if (typeof this !== 'function') {
		throw TypeError('left value need a function')
	}
	context.fn = this
	const args = [...arguments].slice(1)
	return function(..._args) {
		const res = context.fn(args.concat(_args))
		delete context.fn
		return res
	}
}