Can I insert if statement in else statement in JS?

Question

Can I insert if statement in else statement ? The code :

function swicthNum() {
  'use strict';
  var processDoc = document.getElementById('process').innerHTML;
  if (processDoc == 'Dollars to Algerian Dinar') {
    processDoc = 'Algerian Dinar to Dollars';
  } else {
    processDoc = 'Dollars to Algerian Dinar';
  }
  return processDoc;
}
function moneyCalc() {
  'use strict';
  var num = document.getElementById('moneyNum').value,
      lastResultDoc = document.getElementById('lastResult'),
      result = num * 107.39,
      lastResult = document.getElementById('lastResult');
  if (num < 0) {
    lastResult.innerHTML = 'The process don\'t accept negative numbers';
  } else {
    if (processDoc == 'Dollars to Algerian Dinar') {
      lastResult.innerHTML = result;
    } else {
      result = num * 0.0093;
      lastResult.innerHTML = result;
    }
  }
}

<p id="process">
  Dollars to Algerian Dinar
</p>
<button onclick="swicthNum()">Switch!</button>
<br />
<form action="AdvancedFunction.html" method="post">
  <input id="moneyNum" name="" type="number" value="" />
  <input onclick="moneyCalc()" name="" type="submit" value="Calculate" />
</form>
<div id="lastResult">Result</div>

you mean dynamically? what do you want to achieve by doing this? — gurvinder372, Jan 05 '16 at 18:48
@gurvinder372 no ,my code doesn't work give me just why his don't work! — Saad Laggoune, Jan 05 '16 at 19:21
Try to add `alert()` inside every statement to know the achieved condition. — Zakaria Acharki, Jan 05 '16 at 19:26
@ZakariaAcharki i updated the code ,look if i have some errors by yourself — Saad Laggoune, Jan 05 '16 at 19:43

score 0 · Answer 1 · edited Jun 20 '20 at 09:12

0

You definitely can, but in your case you could simply go for:

if (num < 0) {
  lastResult.innerHTML = 'The process don\'t accept negative numbers';
} 
else if (processDoc == 'Dollars to Euro') {
    lastResult.innerHTML = result;
} 
else {
    result = num * 0.0093;
    lastResult.innerHTML = result;
}

It might be simpler to read.

Why your code wasn't working

You set the variable processDoc in a function, so it was not available for the other function: you have to set it globally.
There were spaces at the beginning of the "process"'s innerHTML, so switchNum() never changed its content: using indexOf, we can check if the desired string is contained in the paragraph, but not necessarily equal to the paragraph's content.
You didn't change innerHTML of process at the end of the switchNum function.
On click on 'Calculate', the form was submitted, so it wasn't possible to see the result of the calculation. To prevent that, use return false;.

Working code

function swicthNum() {
  'use strict';
  window.processDoc = document.getElementById('process').innerHTML;
  if (window.processDoc.indexOf('Dollars to Algerian Dinar')>-1) {
    window.processDoc = 'Algerian Dinar to Dollars';
  } else {
    window.processDoc = 'Dollars to Algerian Dinar';
  }
    document.getElementById('process').innerHTML = window.processDoc;
  return window.processDoc;
}
function moneyCalc() {
  'use strict';
  var num = document.getElementById('moneyNum').value,
      lastResultDoc = document.getElementById('lastResult'),
      result = num * 107.39,
      lastResult = document.getElementById('lastResult');
  if (num < 0) {
    lastResult.innerHTML = 'The process don\'t accept negative numbers';
  } else {
    if (window.processDoc == 'Dollars to Algerian Dinar') {
      lastResult.innerHTML = result;
    } else {
      result = num * 0.0093;
      lastResult.innerHTML = result;
    }
  }
}

<p id="process">Dollars to Algerian Dinar</p>
<button onclick="swicthNum()">Switch!</button>
<br />
<form action="#" method="post">
  <input id="moneyNum" name="" type="number" value="" />
  <input onclick="moneyCalc(); return false;" name="" type="submit" value="Calculate" />
</form>
<div id="lastResult">Result</div>

edited Jun 20 '20 at 09:12

Community

1
1

answered Jan 05 '16 at 18:49

Stubborn

995
4
17
30

1

May ignore the brackets also (just to input more faster): `if(num<0)lastResult.innerHTML=...,alert(1);else if(proccessDoc...==...);else ...`. There's the `switch` also if they're many checkments. – Jan 05 '16 at 18:53
2

@ProHands - It is generally bad practice to skip the braces as this can lead to accidental coding mistakes very easily. – jfriend00 Jan 05 '16 at 18:58
thanks man but no, i wan't to use my method not Else if statement but my code doesn't work! – Saad Laggoune Jan 05 '16 at 19:19
@jfriend00 It depends on what you're doing, but there you have to use commas instead of semicolons, nor for everything works when using DOM. – Jan 05 '16 at 19:22
@SaadLaggoune could you be more specific? Please have a look at your browser console and post the errors that it points out :) – Stubborn Jan 05 '16 at 19:24
1

@ProHands - We're clearing advising a newbie here. I wouldn't be going into commas and skipping braces with a Javascript newbie. The advice should be appropriate for the audience. – jfriend00 Jan 05 '16 at 19:24
@jfriend00 give me more info please – Saad Laggoune Jan 05 '16 at 19:26
@SaadLaggoune could you please update the question with the full code and explain what it should do and what isn't working? – Stubborn Jan 05 '16 at 19:27
1

@Stubborn HTML doc in coming – Saad Laggoune Jan 05 '16 at 19:31
@SaadLaggoune sorry for delay, see my updated answer for the working code – Stubborn Jan 05 '16 at 21:20

Can I insert if statement in else statement in JS?

1 Answers1

Why your code wasn't working

Working code