There is no point in return true in a forEach

I assume you mean this:

const testArr = arr => arr[0] === arr[arr.length-1]; // test first and last

const array = [[1, 2], [3, 3]]; 

const testResults = array.map(el => testArr(el)); // map the results
console.log(testResults)

// filter: 

const same = array.filter(el => testArr(el)); // FIND the array that has same first and last 

console.log(same.flat())

You should should every function

const arr = [[1, 2], [3, 3]]; 
const b = arr.every(el => el[0] === el[1]);
console.log(b); // false

This should get the desired result. Just change console.log(true) to whatever you would like to do if they equal each other. This will work on any length of array.

const array = [
  [1, 2],
  [3, 3],
];

array.forEach((el) => {
  if (el[0] === el[el.length - 1]) {
    console.log(true);
  }
});