simple example of uppercase, lowercase and capitalize text

capitaLize.js

/*
simple example to capitalize
*/
function capitaLize() {
    const textbox = document.getElementById("text-box"); //textarea
    const textresult = document.getElementById("text-result"); //result element "<pre>";

    if ((textbox) && (textbox.value) && (textbox.value.toString().trim().length > 0)) {
        textresult.innerText = "";
        const str = textbox.value.toString().trim().toLowerCase(); //turns everything to lowercase
        const length = str.length;

        if (length > 0) {
            textresult.innerText = str.toString().replace(/\S+/g, words => { //separate by word blocks
                return words.charAt(0).toUpperCase() + words.substr(1); //to uppercase first character
            });
            return true;
        }
    }
    //
}

lowerCase.js

/*
simple example to lowercase
*/
function lowerCase() {
    const textbox = document.getElementById("text-box"); //textarea
    const textresult = document.getElementById("text-result"); //result element "<pre>";

    if ((textbox) && (textbox.value) && (textbox.value.toString().trim().length > 0)) {
        textresult.innerText = "";
        const str = textbox.value.toString().trim();
        const length = str.length;
        
        if (length > 0) {
            textresult.innerText = str.toString().toLowerCase();
            return true;
        }
    }
  //
}

upperCase.js

/*
simple example to uppercase
*/
function upperCase() {
    const textbox = document.getElementById("text-box"); //textarea
    const textresult = document.getElementById("text-result"); //result element "<pre>";

    if ((textbox) && (textbox.value) && (textbox.value.toString().trim().length > 0)) {
        textresult.innerText = "";
        const str = textbox.value.toString().trim();
        const length = str.length;
        //
        if (length > 0) {
            textresult.innerText = str.toString().toUpperCase();
            return true;
        }
    }
  //
}