How to redirect URL via JavaScript based on a number (if 1, redirect to A; if 2, to B...)

Question

I want to redirect a visitor based on a variable in their URL. Use case is a quiz with Gravity Forms where the user will be redirected to example.com/processing?quizresult={n}

Where n is a numerical value (0-50).

There are 3 possible outcomes (0-15, 16-30, 31-50).

I’ve found JavaScript to redirect based on if a URL contains a variable, but not a range of variables. Is there a better way than 50 “IF” statements?

<script>
if(document.location.href.indexOf('1') > -1) { 
    document.location.href = 'http://www.example.com/resultA';
}

if(document.location.href.indexOf('2') > -1) { 
    document.location.href = 'http://www.example.com/resultA';
}

if(document.location.href.indexOf('3') > -1) { 
    document.location.href = 'http://www.example.com/resultA';
}

Answer 1

Try this:

• Extract {n} from your url string
• Conditionally redirect according to the value of n

Example:

// extract {n} from example.com/processing?quizresult={n}
const getParamValue = (url, parameterKey) => {
  const [urlWithoutParameters, parameters = ''] = url.split('?'); // ['example.com/processing', 'quizresult=1']
  const paramsArr = parameters.split('&'); // ['quizresult=1']

  for (let i = 0; i < paramsArr.length; i++) {
    const [k, v] = paramsArr[i].split('='); // k = 'quizresult', v = '1'
    if (k === parameterKey) {
      return v;
    }
  }
};

// conditionally redirect to the result urls.
const conditionallyRedirect = (url) => {
  const quizResult = getParamValue(url, 'quizresult');
  if (quizResult >= 0 && quizResult < 16) {
    console.log('resultA');
    // document.location.href = 'http://www.example.com/resultA';
  } else if (quizResult >= 16 && quizResult < 31) {
    console.log('resultB');
    // document.location.href = 'http://www.example.com/resultB';
  } else if (quizResult >= 31 && quizResult <= 50) {
    console.log('resultC');
    // document.location.href = 'http://www.example.com/resultC';
  }
  // do not redirect otherwise
};


// Examples
conditionallyRedirect('example.com/processing?quizresult=1'); // redirects to resultA
conditionallyRedirect('example.com/processing?quizresult=17&someotherparam=whatever'); // redirects to resultB
conditionallyRedirect('example.com/processing'); // does not redirect
conditionallyRedirect('example.com/processing?quizresult=100'); // does not redirect

So this would work for you:

conditionallyRedirect(document.location.href);