An array can contains multiple values. I want to check whether all the values are same or different.
Example
var a = [2, 4, 7, 2, 8]; // all values are not same var b = [2, 2, 2, 2, 2]; // all values are same How can I check it in jquery
- 3Possible duplicate of How to know if two arrays have the same values, How to check if two arrays are equal with JavaScript?Alex K.– Alex K.2016-08-03 12:55:48 +00:00Commented Aug 3, 2016 at 12:55
- you can use underscore.js for the simplicity and use _.difference([2, 4, 7, 2, 8], [2, 2, 2, 2, 2]);Sunil– Sunil2016-08-03 12:58:35 +00:00Commented Aug 3, 2016 at 12:58
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5 Answers
You can try like this:
var a = [2, 4, 7, 2, 8]; var b = [2, 2, 2, 2, 2]; function myFunc(arr){ var x= arr[0]; return arr.every(function(item){ return item=== x; }); } alert(myFunc(a)); alert(myFunc(b));See the MDN for Array.prototype.every()
2 Comments
David Thomas
I'd suggest a slight refinement:
return arr.slice(1).every(v => arr[0]); on the grounds there's no need to check if arr[0] === arr[0]; but it's a micro-optimisation at best; and might not be an optimisation at all, if it takes longer to slice the array than it does to needlessly compare the first array element to itself.
Shan Biswas
Wow, great code, works fine. Thank you @Rahul
Check this solution
function arrayUnique(array) { function onlyUnique(value, index, self) { return self.indexOf(value) === index; } var unique = array.filter( onlyUnique ); return (unique.length == 1); } // usage example: var a = [2, 3, 2, 2, 2]; console.log('Array is unique : ' + arrayUnique(a)); // Array is unique : false var b = [2, 2, 2, 2, 2]; console.log('Array is unique : ' + arrayUnique(b)); // Array is unique : true 
Comments
It's possible using an array reduce:
Array.prototype.areAllTheSame = function() { if(!this.length) return false return this.reduce(function(p, c) { return [c, c==p[0] && p[1]] }, [this[0], true])[1] } var arr = [1,2,3,4] var arr2 = [2,2,2,2] arr.areAllTheSame() //-->false arr2.areAllTheSame() //-->true 
Comments
If you have access to Set:
var a = [2, 4, 7, 2, 8]; var b = [2, 2, 2, 2, 2]; function onlyOneValue(arr){ return [...new Set(arr)].length < 2; } document.write(onlyOneValue(a) + '<br>'); document.write(onlyOneValue(b));