javascript - How to pass arguments to a function with one passed? (ES6) -

there function 3 arguments set default:

function func( = 1, b = 2, c = 3 ) {     console.log(a, b, c); } 

how pass arguments function 1 passed? example:

func(10, , 30); 

you use undefined, value undefined variables default parameters:

in javascript, parameters of functions default undefined.

the default check works like

b = b !== undefined ? b : 2  

function func(a = 1, b = 2, c = 3) {      console.log(a, b, c);  }    func(10, undefined, 30);

wiki