javascript - Regarding the problem of function calling, the loop body of the click event cannot loop these four functions, but the loop body can be looped using alert.
It’s okay for the click event to call each function individually, but it won’t work after writing the loop body. The function alone is fine. I always write one test one at a time, and then the click event can be displayed individually, but there is a problem if there is a loop body.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
*{padding:0;margin: 0;}
#btn{position: absolute;top:0;left:300px;}
p{width: 50px;height:50px;position: absolute;top:0;left:0;background:green;font-size: 30px; text-align:center;color:red;line-height: 50px;cursor: pointer;}
</style>
<script>
window.onload=function () {
var btn = document.getElementById("btn");
var op = document.getElementsByTagName("p");
function first() {
{
// btn.style.display = "none";
for (var i = 0; i < 5; i++) {
document.body.innerHTML += '<p>' + i + '</p>';
}
for (i = 0; i < op.length; i++) {
//op[i].index = i;
if (i > op.length / 2) {
op[i].style.left = i * 60 + "px";
op[i].style.top = (i - parseInt(op.length / 2)) * 60 + "px";
}
else {
// alert(i);
op[i].style.top = (parseInt(op.length / 2) - i) * 60 + "px";
op[i].style.left = i * 60 + "px";
}
}
}
}
function second() {
// btn.style.display="none";
for (var i = 0; i < 5; i++) {
document.box2.innerHTML += '<p id="box">' + i + '</p>';
}
for ( i = 0; i < op.length; i++) {
//op[i].index = i;
if(i>op.length/2){
op[i].style.left = (op.length-i -1)* 60 + "px";
op[i].style.top=i*60+"px";
}
else {
// alert( i);
op[i].style.top = i* 60 + "px";
op[i].style.left = i * 60 + "px";
}
}
}
function three() {
//btn.style.display = "none";
for (var i = 0; i < 5; i++) {
document.body.innerHTML += '<p>' + i + '</p>';
}
for (i = 0; i < op.length; i++) {
//op[i].index = i;
if (i > op.length / 2) {
op[i].style.left = (i - parseInt(op.length / 2)) * 60 + "px";
op[i].style.top = i * 60 + "px";
}
else {
// alert( i);
op[i].style.top = i * 60 + "px";
op[i].style.left = ( parseInt(op.length / 2) - i) * 60 + "px";
}
}
}
function four() {
//btn.style.display="none";
for (var i = 0; i < 5; i++) {
document.body.innerHTML += '<p>' + i +'</p>';
}
for ( i = 0; i < op.length; i++) {
op[i].index = i;
if(i>op.length/2){
op[i].style.left = i * 60 + "px";
op[i].style.top=(op.length-i-1)*60+"px";
}
else {
op[i].style.top = i * 60 + "px";
op[i].style.left = i * 60 + "px";
}
}
}
var k=0;
btn.onclick = function () {
//if(k==0){alert(1)}
if(k==0){first()}
if(k==1){second()}
if(k==2){three()}
if(k==3){four()}
k++;
// first();
//second();
//three();
//four();
}
};
</script></head>
<body>
<input id="btn" type="button" value="Click to generate li"/>
</body>
</html>
