메서드 (toUpperCase / toLowerCase)

toUpperCase() / toLowerCase()

문자열을 대문자로 변경 : 반환(문자열) / 문자열을 소문자로 변경 : 반환(문자열)

번호	기본값	메서드	리턴값
1	javascript	toUpperCase	JAVASCRIPT
2	JAVASCRIPT	toLowerCase	javascript

    const str1 = "javascript";
    const currentStr1 = str1.toUpperCase();

    document.querySelector(".sample02_N1").innerHTML = "1";
    document.querySelector(".sample02_Q1").innerHTML = "javascript";
    document.querySelector(".sample02_M1").innerHTML = "toUpperCase";
    document.querySelector(".sample02_P1").innerHTML = currentStr1;

    const str2 = "JAVASCRIPT";
    const currentStr2 = str1.toLowerCase();

    document.querySelector(".sample02_N2").innerHTML = "2";
    document.querySelector(".sample02_Q2").innerHTML = "JAVASCRIPT";
    document.querySelector(".sample02_M2").innerHTML = "toLowerCase";
    document.querySelector(".sample02_P2").innerHTML = currentStr2;