+a.slice(-1) what does it mean javascript string code example

Example 1: js string slicing

const str = 'The quick brown fox jumps over the lazy dog.';

console.log(str.slice(31));
// expected output: "the lazy dog."

console.log(str.slice(4, 19));
// expected output: "quick brown fox"

Example 2: slice string js

const str = 'The quick brown fox jumps over the lazy dog.';

console.log(str.slice(31)); // expected output: "the lazy dog."

console.log(str.slice(4, 19)); // expected output: "quick brown fox"

console.log(str.slice(-4)); // expected output: "dog."

console.log(str.slice(-9, -5)); // expected output: "lazy"

// source : https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Objets_globaux/String/slice