Default argument values in JavaScript functions [duplicate]

Answer 1

function func(a, b)
{
  if (typeof a == 'undefined')
    a = 10;
  if (typeof b == 'undefined')
    b = 20;
  // do what you want ... for example
  alert(a + ',' + b);
}

in shorthand

function func(a, b)
{
  a = (typeof a == 'undefined')?10:a;
  b = (typeof b == 'undefined')?20:b;

  // do what you want ... for example
  alert(a + ',' + b);
}