我的脚本有什么问题？ 它不返回带有“ if语句”的消息

Question

i've made this script but it won't work properly, what i want is an input box, and if i use it the site returns some text.

 function myFunction(); var text_input = document.getElementById("input001").value; if (text_input == "4") { document.getElementById("message001").innerText = "Correct!"; } else { document.getElementById("message001").innerText = "nope"; } } 

 <div class=questions> <p>What is 9-5?</p> </div> <input id="input001" type="text" /> <button onclick="myFunction()">Check</button> <p id="message001"></p> 

Answer 1

The problem is you are closing your function with a semi colon.

Instead, put an opening parenthesis

function myFunction(){
        var text_input=document.getElementById("input001").value;
        if (text_input=="4"){
            document.getElementById("message001").innerText="Correct!";
            }
        else{
            document.getElementById("message001").innerText="nope";
            }
     }

Answer 2

function myFunction(){//changed line no need to add ; here
var text_input = document.getElementById("input001").value;
 if (text_input == "4") {
   document.getElementById("message001").innerText = "Correct!";
  } else {
   document.getElementById("message001").innerText = "nope";
  }
}

Answer 3

You have the wrong format for function definition

you just need { after creating a function for the scope

function myFunction(){
   // your code
}

 function myFunction(){ var text_input=document.getElementById("input001").value; if (text_input=="4"){ document.getElementById("message001").innerText="Correct!" } else{ document.getElementById("message001").innerText="nope" } } 

 <!--first question--> <div class=questions> <p>What is 9-5?</p> </div> <input id="input001" type="text" /> <button onclick="myFunction()">Check</button> <p id="message001"></p> 

Answer 4

 function myFunction() { var text_input = document.getElementById("input001").value; if (text_input == "4") { document.getElementById("message001").innerText = "Correct!"; } else { document.getElementById("message001").innerText = "nope"; } } 

 <div class=questions> <p>What is 9-5?</p> </div> <input id="input001" type="text" /> <button onclick="myFunction()">Check</button> <p id="message001"></p> 

You have syntax errors. Find This Example, It will work.

Answer 5

Apart from the fact that you declared only a function with an error (notice a semicolon right after function name), your code doesn't work because you are not passing a function in button's onclick attribute - you're just passing the return value of that function there. You should have <button onclick="myFunction">Check</button> there instead.

Below the correct code:

function myFunction() {
  var text_input = document.getElementById("input001").value;
  if (text_input == "4") {
    document.getElementById("message001").innerText = "Correct!";
  } else {
    document.getElementById("message001").innerText = "nope";
  }
}

<div class=questions>
  <p>What is 9-5?</p>
</div>

<input id="input001" type="text" />
<button onclick="myFunction">Check</button>
<p id="message001"></p>