Javascript/getElementsByClassName

abc

b

bc

ac

c

function a (){
  var a = document.getElementsByClassName("a");
  for( var i = a.length; i--; ) {
	a[i].style.color = "orange" ;
  }
}
function b (){
  var b = document.getElementsByClassName("b");
  for( var i = b.length; i--; ) {
	b[i].style.color = "blue" ;
  }
}
function c (){
  var c = document.getElementsByClassName("c");
  for( var i = c.length; i--; ) {
	c[i].style.color = "pink" ;
  }
}
	

function s2Func(){
  var s2Class = document.getElementsByClassName("s2Class");
  s2Class[1].style.color = "red";
}