Answers for "check if a letter is uppercase javascript\"

check if letter is uppercase javascript

const isUpperCase = (string) => /^[A-Z]*$/.test(string)

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

how to check if a letter is capital in javascript

// program to convert first letter of a string to uppercase
function capitalizeFirstLetter(str) {

    // converting first letter to uppercase
    const capitalized = str.charAt(0).toUpperCase() + str.slice(1);

    return capitalized;
}

// take input
const string = prompt('Enter a string: ');

const result = capitalizeFirstLetter(string);

console.log(result);