índice de vs findIndex
/* findIndex vs indexOf methods.
All return -1 when no value is found. */
let myArray = [9, 2, 2, 8, 4, 2, 5, 6, 2, 9];
// findIndex(arg => argCondition): return the first index
// for which the given function is true.
myArray.findIndex(x => x > 2); // → 3
// indexOf(value): return the value's first index.
myArray.indexOf(2); // → 1
// lastIndexOf(value): return the value's last index.
myArray.lastIndexOf(2); // → 8
// indexOf(value, start): return the value's first index,
// starting at the given position.
myArray.indexOf(2, 3); // → 5
// lastIndexOf(value, stop): return the value's last index,
// stopping at the given position.
myArray.lastIndexOf(2, 3); // → 2
Intra