return 문은 함수에서 결괏값을 반환할 때 사용합니다.
function func4(){
let str = "함수가 실행되었습니다.";
return str;
}
let value = func4();
document.write(value);function func6(){
document.write("함수가 출력되었습니다6.");
return;
}
func6();Last updated
function func5(num1, num2){
return num1 + num2;
}
let result = func5(100, 200);
document.write(result);function testAvg(arrData){
let sum = 0;
for( let i=0; i<arrData.length; i++ ){
sum += Number(prompt(arrData[i] + "점수는?", "0"));
}
let avg = sum / arrData.length;
return avg;
}
let arrSubject = ["국어", "수학"];
let result = testAvg(arrSubject);
document.write(result);document.getElementById("img").setAttribute("alt","산 이미지입니다.");
let prev = document.querySelector(".prev");
let next = document.querySelector(".next");
let image = document.getElementById("img");
let num = 1;
prev.addEventListener("click", function(){
if(num == 1){
alert("처음 이미지입니다.")
return;
}
num--;
image.setAttribute("src","img/pic_"+ num +".jpg")
console.log(num);
});
next.addEventListener("click", function(){
if(num == 8){
alert("마지막 이미지입니다.")
return;
}
num++;
image.setAttribute("src","img/pic_"+ num +".jpg")
console.log(num);
});<body>
<div id="galleryZone">
<p><img id="photo" src="img/pic_1.jpg" alt="이미지1" style="width: 500px;"></p>
<div>
<button onclick="gallery(0)">이전</button>
<button onclick="gallery(1)">다음</button>
</div>
</div>
<script>
let num = 1;
function gallery(direct){
if(direct){
if(num == 8){
return;
}
num++;
} else {
if(num == 1) {
return;
}
num--;
}
console.log(num);
let imgTag = document.getElementById("photo");
imgTag.setAttribute("src","img/pic_"+ num +".jpg");
}
</script>
</body>