我在javascript中创建了2个函数,这些函数会在click事件上触发,问题是在for
循环后,警报不会执行。
function myfunc() {
for (var i = 0; i < 4; i++) {
document.getElementsByTagName("h1")[i].style.color="red";
}
alert("alert 1"); //this should be executed after the for since it is part of the function code.
}
function myfunc2() {
for (var j = 0; j < 4; j++) {
document.getElementsByTagName("h1")[j].style.color="navy";
}
alert("alert 2"); //this should be executed after the for since it is part of the function code
}
<h1 onClick="myfunc()">primo h1</h1>
<h1 onClick="myfunc2();">secondo h1</h1>
最佳答案
应用新的样式属性之前,您需要检查DOM中有多少h1
个标记。您实际上是在尝试对undefined
进行更改。
var elements = document.getElementsByTagName("h1");
function myfunc() {
for (var i = 0; i < elements.length; i++) {
elements[i].style.color="red";
}
alert("alert 1"); //this should be executed after the for since it is part of the function code.
}
function myfunc2() {
for (var j = 0; j < elements.length; j++) {
elements[j].style.color="navy";
}
alert("alert 2"); //this should be executed after the for since it is part of the function code
}
<h1 onClick="myfunc()">primo h1</h1>
<h1 onClick="myfunc2();">secondo h1</h1>