try throw catch finally


 s

try {
  // Code that might throw an error
  let result = someUndefinedVariable + 10;
  console.log(result); // This line will not be executed
} catch (error) {
  // Code to handle the error
  console.log('An error occurred:', error);
}

s


try throw catch


throw is in try block , but it is condition based-> in try if condtion true throw this error like that


<!DOCTYPE html>
<html>
<body>

<p>Please input a number between 5 and 10:</p>

<input id="demo" type="text">
<button type="button" onclick="myFunction()">Test Input</button>
<p id="p01"></p>

<script>
function myFunction() {
  const message = document.getElementById("p01");
  message.innerHTML = "";
  let x = document.getElementById("demo").value;
  try {
    if(x.trim() == ""throw "empty";
    if(isNaN(x)) throw "not a number";
    x = Number(x);
    if(x < 5throw "too low";
    if(x > 10throw "too high";
  }
  catch(err) {
    message.innerHTML = "Input is " + err;
  }
}
</script>

</body>
</html>


try throw catch finally


after execution of try or catch

regradless of result it will implment 

means after eexuting try catech, we wann implement input element to inital value


<!DOCTYPE html>

<html>

<body>


<h2>JavaScript try catch</h2>


<p>Please input a number between 5 and 10:</p>


<input id="demo" type="text">

<button type="button" onclick="myFunction()">Test Input</button>


<p id="p01"></p>


<script>

function myFunction() {

  const message = document.getElementById("p01");

  message.innerHTML = "";

  let x = document.getElementById("demo").value;

  try { 

    if(x.trim() == "")  throw "is empty";

    if(isNaN(x)) throw "is not a number";

    x = Number(x);

    if(x > 10)   throw "is too high";

    if(x < 5)  throw "is too low";

  }

  catch(err) {

    message.innerHTML = "Input " + err;

  }

  finally {

    document.getElementById("demo").value = "rfhf";

  }

}

</script>


</body>

</html>




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