Edit in JSFiddle

var cont = document.getElementById('rs');
var passthru = function(literlas, ...substitutions){
	let rs = "";
  
  // 처리자 개수만큼 반복
  for(let i = 0; i < substitutions.length; i++){
  	rs += literlas[i]
    rs += substitutions[i]
  }
  
  // 마자막 리터럴 추가
  rs += literlas[ literlas.length - 1 ]
  
  return rs
}
var raw = function(literals, ...substitutions){
	let rs = "";
  for(let i = 0; i < substitutions.length; i++){
  	rs += literals.raw[i]
    rs += substitutions[i]
  }
  
  rs += literals.raw[ literals.length - 1]
  
  return rs
}

let count = 10,
	price = 0.25,
  msg = passthru`${count} items cost $${(count * price).toFixed(2)}.`;
  
cont.textContent = msg
cont.textContent += `\n${'#'.repeat(64)}\n`
cont.textContent +=  `Multiline\nString`
cont.textContent +=  `\n`
cont.textContent +=  "String.raw`Multiline\\nString`: " + String.raw`Multiline\nString`
cont.textContent +=  `\n`
cont.textContent += "raw`Multiline\\nString`: " + raw`Multiline\nString`
cont.textContent += `\n${'#'.repeat(64)}\n`

<pre id="rs"></pre>