我如何使用 javascript 获得单选按钮的值？

Question

Make my code work please,

 function myFunction() { var x = document.getElementById("myRadio").value; document.getElementById("demo").innerHTML = x; }

 <input type="radio" name="colors" value="-161" id="myRadio">first number <input type="radio" name="s" value="5" id="myRadio">sec number <p>Click the "Try it" button to display the value of the value attribute of the radio button.</p> <button onclick="myFunction()">Try it</button> <p id="demo"></p>

Answer 1

Your radio button <input type="radio" value="myValue" id="myRadio" />

Your Button <button onclick="myFunction()">Try it</button>

Run function when button click

function myFunction() { 
   var x = document.getElementById("myRadio").value; 
   document.getElementById("demo").textContent = x;
}

Answer 2

I believe you want the system to be able to display which radio button is checked and then display the value (-161 or 5) when the button is click.

In that case, you can loop thru the radio buttons to check which one is checked and then get the value.

please use the following

 function myFunction() { // var x = document.getElementById("myRadio").value; var ele = document.getElementsByName('colors'); for(i = 0; i < ele.length; i++) { if(ele[i].checked){ x=ele[i].value;} } document.getElementById("demo").innerHTML = x; }

 <input type="radio" name="colors" value="-161" id="myRadio">first number <input type="radio" name="colors" value="5" id="myRadio">sec number <p>Click the "Try it" button to display the value of the value attribute of the radio button.</p> <button onclick="myFunction()">Try it</button> <p id="demo"></p>