Javascript/charAt

解説文字列の中から指定したインデックスの文字を抜き出す

sample1

sample1Code

function s1Func(){
  var s1Input = document.getElementById("s1Input").value;
  var s1Str = "abcdefghijklmnopqrstuvwxyz";
  var s1 = s1Str.charAt(s1Input);
  var s1Div = document.getElementById("s1Div");
  s1Div.textContent = s1;
}

sample2

sample2code

function s2Func(){
  var s2Str = "abcdefghijklmnopqrstuvwxyz";
  var s2Rnd = Math.floor(Math.random()*s2Str.length);
  var s2 = s2Str.charAt(s2Rnd);
  var s2Div = document.getElementById("s2Div");
  s2Div.innerText = s2;
}