Javascript 替换同一字段中的函数

Javascript replace function in same field

我的代码

<!DOCTYPE html>
<html>
<body>

<input type="text" id="text" value=""><br>


<button onclick="myFunction()">Submit</button>


<script>
function myFunction() {

var str = document.getElementById("text"); 
var res = str.replace("1", "2");
document.getElementById("text") = res;


}
</script>

在输入字段中,我在(单击)提交时从用户那里获取了一些输入,我想用 2 替换所有 1,我想在同一字段中显示结果,但它不起作用..

这就是你想要的:

function myFunction() {
  var inputElt = document.getElementById("text");
  var res = inputElt.value.replace("1", "2");
  inputElt.value = res;
}

您需要获取值

function myFunction() {
    //getElementById returns dom object
    var el = document.getElementById("text");

    //you want to replace its value
    var str = el.value;

    //use a simple regex to replace all instances
    var res = str.replace(/1/g, "2");

    //set the value property of the target element
    el.value = res;
}

演示:Fiddle, short version

您的线路:

document.getElementById("text") = res;

相反,应如下所示:

document.getElementById("text").value = res;