How can I check if the array of objects have duplicate property values?

Question

I need some help with iterating through array, I keep getting stuck or reinventing the wheel.

values = [     { name: 'someName1' },     { name: 'someName2' },     { name: 'someName1' },     { name: 'someName1' } ] 

How could I check if there are two (or more) same name value in array? I do not need a counter, just setting some variable if array values are not unique. Have in mind that array length is dynamic, also array values.

Answer 1

Use array.prototype.map and array.prototype.some:

var values = [     { name: 'someName1' },     { name: 'someName2' },     { name: 'someName4' },     { name: 'someName2' } ];  var valueArr = values.map(function(item){ return item.name }); var isDuplicate = valueArr.some(function(item, idx){      return valueArr.indexOf(item) != idx  }); console.log(isDuplicate);