Discussion on: How To Efficiently Get The Last Element Of An Array In JavaScript

[codingjlu]

I think this is a better way (it took me a lot of work):

function lastElement(arr) {
  switch (arr.length) {
    case 1:
      return arr[0];
    case 2:
      return arr[1];
    case 3:
      return arr[2];
    case 4:
      return arr[3];
    case 5:
      return arr[4];
    case 6:
      return arr[5];
    case 7:
      return arr[6];
    case 8:
      return arr[7];
    case 9:
      return arr[8];
    case 10:
      return arr[9];
    case 11:
      return arr[10];
    case 12:
      return arr[11];
    case 13:
      return arr[12];
    case 14:
      return arr[13];
    case 15:
      return arr[14];
    case 16:
      return arr[15];
    case 17:
      return arr[16];
    case 18:
      return arr[17];
    case 19:
      return arr[18];
    case 20:
      return arr[19];
    case 21:
      return arr[20];
    case 22:
      return arr[21];
    case 23:
      return arr[22];
    case 24:
      return arr[23];
    case 25:
      return arr[24];
    case 26:
      return arr[25];
    case 27:
      return arr[26];
    case 28:
      return arr[27];
    case 29:
      return arr[28];
    case 30:
      return arr[29];
    case 31:
      return arr[30];
    case 32:
      return arr[31];
    case 33:
      return arr[32];
    case 34:
      return arr[33];
    case 35:
      return arr[34];
    case 36:
      return arr[35];
    case 37:
      return arr[36];
    case 38:
      return arr[37];
    case 39:
      return arr[38];
    case 40:
      return arr[39];
    case 41:
      return arr[40];
    case 42:
      return arr[41];
    case 43:
      return arr[42];
    case 44:
      return arr[43];
    case 45:
      return arr[44];
    case 46:
      return arr[45];
    case 47:
      return arr[46];
    case 48:
      return arr[47];
    case 49:
      return arr[48];
    case 50:
      return arr[49];
    case 51:
      return arr[50];
    case 52:
      return arr[51];
    case 53:
      return arr[52];
    case 54:
      return arr[53];
    case 55:
      return arr[54];
    case 56:
      return arr[55];
    case 57:
      return arr[56];
    case 58:
      return arr[57];
    case 59:
      return arr[58];
    case 60:
      return arr[59];
    case 61:
      return arr[60];
    case 62:
      return arr[61];
    case 63:
      return arr[62];
    case 64:
      return arr[63];
    case 65:
      return arr[64];
    case 66:
      return arr[65];
    case 67:
      return arr[66];
    case 68:
      return arr[67];
    case 69:
      return arr[68];
    case 70:
      return arr[69];
    case 71:
      return arr[70];
    case 72:
      return arr[71];
    case 73:
      return arr[72];
    case 74:
      return arr[73];
    case 75:
      return arr[74];
    case 76:
      return arr[75];
    case 77:
      return arr[76];
    case 78:
      return arr[77];
    case 79:
      return arr[78];
    case 80:
      return arr[79];
    case 81:
      return arr[80];
    case 82:
      return arr[81];
    case 83:
      return arr[82];
    case 84:
      return arr[83];
    case 85:
      return arr[84];
    case 86:
      return arr[85];
    case 87:
      return arr[86];
    case 88:
      return arr[87];
    case 89:
      return arr[88];
    case 90:
      return arr[89];
    case 91:
      return arr[90];
    case 92:
      return arr[91];
    case 93:
      return arr[92];
    case 94:
      return arr[93];
    case 95:
      return arr[94];
    case 96:
      return arr[95];
    case 97:
      return arr[96];
    case 98:
      return arr[97];
    case 99:
      return arr[98];
    case 100:
      return arr[99];
    default:
      return arr[arr.length - 1]; // fallback for less efficient way
  }
}

If anyone likes it you can request me for some more. All that hard work 😅

And of course, the less efficient but nice one-liner:

const lastElem = arr => arr[Math.abs(~arr.lastIndexOf(arr[arr.length - 1])) - 1];