根据单选按钮设置input[text]值

<input type="text" id="inputText">
<input type="radio" name="option" value="option1"> Option 1
<input type="radio" name="option" value="option2"> Option 2
<input type="radio" name="option" value="option3"> Option 3

var inputText = document.getElementById("inputText");
var radioButtons = document.getElementsByName("option");

for (var i = 0; i < radioButtons.length; i++) {
  radioButtons[i].addEventListener("change", function() {
    inputText.value = this.value;
  });
}