JAVASCRIPT

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();
}

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"));

js if text contains lowercase

function hasLowerCase(str) {
    return str.toUpperCase() != str;
}

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