js how to tell of a character is lowercase code example

Example 1: how to check string uppercase or lowersace using regex javascript

var regex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[!#\*\?])(?=.{8,})/;

Example 2: how to find if given character in a string is uppercase or lowercase in javascript

var str = S;

  if (str == str.toUpperCase())
  {
    console.log(" Uppercase");
  }
  else
  {
    console.log("Lowercase");
  }