function fun(p1,p2 = "20"){
    
    console.log(arguments.length)
    console.log(p1 === arguments[0])
    console.log(p2 === arguments[1])
    p1 = "11"
    p2 = "22"
    console.log(p1 === arguments[0])
    console.log(p2 === arguments[1])

}
fun()