Answers for "how to check if a letter is lowercase in javascript"

javascript check if all capital letter

function isUpper(str) {
    return !/[a-z]/.test(str) && /[A-Z]/.test(str);
}

isUpper("FOO"); //true
isUpper("bar"); //false
isUpper("123"); //false
isUpper("123a"); //false
isUpper("123A"); //true
isUpper("A123"); //true
isUpper(""); //false

js test letter lowercase

if (character == character.toLowerCase())
{
  // The character is lowercase
}
else
{
  // The character is uppercase
}
//The problem with this answer is, 
//that some characters like numbers or punctuation 
//also return true when checked for lowercase/uppercase.

// this is the solution for it:
function isLowerCase(str)
{
    return str == str.toLowerCase() && str != str.toUpperCase();
}

how to check string uppercase or lowersace using regex javascript

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

check if string contains lowercase javascript

// A minified version of the other one:
const hasLowerCase= s => s.toUpperCase() != s;

console.log("HeLLO: ", hasLowerCase("HeLLO"));
console.log("HELLO: ", hasLowerCase("HELLO"));

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");
  }