Javascript: Comparing SINGLE Value Against MULTIPLE Values with OR Operands

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Check variable equality against a list of values
Javascript if statement with multiple permissible conditions

I must click the same 21 of 253 items (li) in a dropdown list (ul).

Scrolling I'll have to do this for the same list on 500+ pages, I figured I could Javascript inject each ul, loop through and click each li which happens to be one of the 21. It seems I cannot do something like

 if(item[i] === ('aasdf'|'basdf'|'cwefw'|'asdfd'|'trehe'|'ferth'|'erthg'|'erthh'|'ierth'|'jeth'|'kerth'|'lerth'|'merth'|'psdfg'|'gregq'|'rsrgs'|'sress'|'srget'|'sergu'|'sdfgsv'))

Is there a syntactically cleaner way of writing this ugly if statement below?

var item = document.getElementById('myDropdownList').getElementsByTagName('li');

for (i=0;i<item.length;i++){

    if(item[i].innerText === 'Argentina' | item[i].innerText === 'Australia' | item[i].innerText === 'Brazil' | item[i].innerText === 'Canada' | item[i].innerText === 'China' | item[i].innerText === 'Colombia' | item[i].innerText === 'France' | item[i].innerText === 'Germany' | item[i].innerText === 'Indonesia' | item[i].innerText === 'India' | item[i].innerText === 'Italy' | item[i].innerText === 'Japan' | item[i].innerText === 'Malaysia' | item[i].innerText === 'Mexico' | item[i].innerText === 'Philippines' | item[i].innerText === 'Russia' | item[i].innerText === 'South Africa' | item[i].innerText === 'Sweden' | item[i].innerText === 'Switzerland' | item[i].innerText === 'United Kingdom' | item[i].innerText === 'USA'){

    item[i].click();

    }

}

Are you sure you need to `click()` them? I'm quite sure there is a better option. — Bergi, Dec 19 '12 at 18:53

score 11 · Accepted Answer · edited Sep 16 '22 at 20:19

You could use a variable and multiple comparison, but that's still lengthy:

var text = item[i].innerText;
if (text === 'Argentina' || text === 'Australia' || text === 'Brazil' || text === 'Canada' || text === 'China' || text === 'Colombia' || text === 'France' || text === 'Germany' || text === 'Indonesia' || text === 'India' || text === 'Italy' || text === 'Japan' || text === 'Malaysia' || text === 'Mexico' || text === 'Philippines' || text === 'Russia' || text === 'South Africa' || text === 'Sweden' || text === 'Switzerland' || text === 'United Kingdom' || text === 'USA')

Or you could just use an array and check if the string is contained in it.

var matches = ['Argentina','Australia','Brazil','Canada','China','Colombia','France','Germany','Indonesia','India','Italy','Japan','Malaysia','Mexico','Philippines','Russia','South Africa','Sweden','Switzerland','United Kingdom','USA'];
if (~ matches.indexOf(item[i].innerText) …

Yet, for the complicated != -1 comparison and the lack of native indexOf in older IEs, people tend to use regexes:

var regex = /Argentina|Australia|Brazil|Canada|China|Colombia|France|Germany|Indonesia|India|Italy|Japan|Malaysia|Mexico|Philippines|Russia|South Africa|Sweden|Switzerland|United Kingdom|USA/
if (regex.test(item[i].innerText)) …

Sounds like `1`? But I'm sure there is a question on explaining that... — Bergi, Dec 19 '12 at 19:02
I'm actually thinking of using `~~X` (dubbing it the "circa operator") instead of `0|X` for casting to int. — John Dvorak, Dec 19 '12 at 19:06
Thank you, & also for all these ~ operators, I have more to research now :) — AlecPerkey, Dec 19 '12 at 19:17

score 5 · Answer 2 · answered Dec 19 '12 at 18:51

var options = ['Argentina', 'Australia', 'Brazil', 'Canada', ...];
if (options.indexOf(item[i].innerText) !== -1){
  // item[i] was found in options
}

Something like that? use Array.indexOf (Unless I've mis-read the question? In which case post a comment and I'll do my best to re-work my answer)

Javascript: Comparing SINGLE Value Against MULTIPLE Values with OR Operands

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