how to get a function that returns first element in array javascript code example

Example 1: javascript take first element of array

const array = [1,2,3,4,5];
const firstElement = array.shift();

// array -> [2,3,4,5]
// firstElement -> 1

Example 2: Return the first element of the array javascript

var studentDetails=
[
   {
      "firstName":"John"
   },
   {
      "firstName":"David"
   },
   {
      "firstName":"Bob"
   },
   {
      "firstName":"Mike"
   },
   {
      "firstName":"Carol"
   }
]
var firstObjectValue = "";
if(studentDetails.length > 1){
   for(var index=0;index< studentDetails.length;index++){
      firstObjectValue=studentDetails[index].firstName;
      break;
   }
} else {
   firstObjectValue=undefined;
}
if(firstObjectValue!=undefined)
   console.log(firstObjectValue);
else
console.log("There is no element in the array");