问题
So I only have 6 lines of code in my page.js file and they are:
document.getElementById("desired").addEventListener("blur", gradeChange());
document.getElementById("calculate").addEventListener("click", gradeChange());
function gradeChange() {
var dog = document.getElementById("desired").value;
console.log(dog);
}
And in my page.html I have:
<input id="desired" type="text">
and somewhere else:
<button id="calculate" type="button">Calculate</button>
I thought it would work without the button, so that when I typed something in the textbox and then left the textbox, it would show up in the log. But nothing showed up, so I added the button to make it more straight forward. Still, it did nothing in the log. Any idea why nothing is showing up?
回答1:
gradeChange() calls the function gradeChange
document.getElementById("desired").addEventListener("blur", gradeChange());
document.getElementById("calculate").addEventListener("click", gradeChange());
Change gradeChange() to gradeChange
document.getElementById("desired").addEventListener("blur", gradeChange);
document.getElementById("calculate").addEventListener("click", gradeChange);
来源：https://stackoverflow.com/questions/27559438/javasctipt-function-running-without-being-called