how to get first array of elements in javascirpt code example

Example 1: get first 10 items of array javascript

const list = ['apple', 'banana', 'orange', 'strawberry']
const size = 3
const items = list.slice(0, size) // res: ['apple', 'banana', 'orange']

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");