Always check for statement update

Question

Sorry about question title I didn't know what to type.

I want to know how you always check for statement update here is what I mean and here is my code:

// This Works
var car = $( "div#car" ).text();
if (car == 0) {
  document.getElementById("car").value = "Some_value";

} else if (car == 1) {
  document.getElementById("car").value = "Some_value";

}

I want always check for car value. When I write that code to console it only runs once. I want the code to repeat itself. I tried this but the code doesn't work in function. Why?

// Doesn't work
var car = $( "div#car" ).text();
function checkcar() {
  if (car == 0) {
    document.getElementById("car").value = "Some_value";
  } else if (car == 1) {
    document.getElementById("car").value = "Some_value";
  }
}

So how to check for car value and always do/repeat the if else statement...

@Addis the problem is the code inside the functiion doesn't work,the code without checkcar() works fine — Aland Sleman, Nov 22 '19 at 17:38
When you are calling this function? Currently you are using car as global please check, will you overwrite your car value? — Devraj verma, Nov 22 '19 at 17:39
@Devrajverma car value is assigned before the function and yes i overwrite the value — Aland Sleman, Nov 22 '19 at 17:41
What do you mean by always check the car value. Bind it to an event so that it can be checked when you need it. And if you don't want that you can use a sync time to execute function — Sachin Bahukhandi, Nov 22 '19 at 17:42
@Devrajverma the code checks for car value only once i want to check for it always if it's 0 or 1 change the car value... — Aland Sleman, Nov 22 '19 at 17:48
If you "continuously run the if statement" the browser would crash, since it all it would be doing is running the code. Move the `var car = $( "div#car" ).text();` into the function and write `while (true) { checkcar(); }` and see what happens. — Heretic Monkey, Nov 22 '19 at 17:48
As @SachinBahukhandi says, you likely want to react to when the value changes, rather than "continuously check". So, the question is, why is the text of the `div` changing? Hook into that code instead. — Heretic Monkey, Nov 22 '19 at 17:50
@HereticMonkey is right. Better bind it on the `change` event of a select box. So once you change it you can see the change — Sachin Bahukhandi, Nov 22 '19 at 17:53
@HereticMonkey when i do that the browser tab crashes :/ weird — Aland Sleman, Nov 22 '19 at 17:57
Great! That doesn't really answer the question of why the text is changing. If you have control over why that text is changing, you can just use that. Otherwise, I'll point you to another event you can listen for that occurs when the text is modified. — Heretic Monkey, Nov 22 '19 at 18:12
Possible duplicate of [jQuery Event : Detect changes to the html/text of a div](https://stackoverflow.com/questions/15657686/jquery-event-detect-changes-to-the-html-text-of-a-div) — Heretic Monkey, Nov 22 '19 at 18:12

score 2 · Accepted Answer · answered Nov 22 '19 at 18:05

2

Here I did it for you. I used it using jQuery.

Hope it helps. Using both select and Textbox.

function checkcar(opt) {
 var v= parseInt($(opt).val());
    if(v==0)
        alert("Zero");
    else if(v==1)
        alert("One");
    else
        alert("Invalid");
}
$(function(){
  $("#car1").change(function(){
    checkcar(this);
  });
  $("#car2").keyup(function(){
    checkcar(this);
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form>
<select id="car1">
<option value="SELECT">SELECT</option>
<option value="0">Value 0</option>
<option value="1">Value 1</option>
</select>
<input type="text" id="car2"/>
</form>

answered Nov 22 '19 at 18:05

Sachin Bahukhandi

2,378
20
29

Thank you so much i appreciate it. It will help me alot – Aland Sleman Nov 22 '19 at 18:13
Marked!,Yes it will definitely help me :) – Aland Sleman Nov 22 '19 at 18:20
Thank you. jQuery is easy to master. Good luck – Sachin Bahukhandi Nov 22 '19 at 18:23

Always check for statement update

1 Answers1