JS Code Samples

jscodesamples.js

// What would be the outcome of this statement?
const [a, b] = [10, 20];









// What is the "..." in following statement? What does it do?
const [a, b, ...rest] = [10, 20, 30, 40, 50];








// What is this statement doing?
const { a, b } = response;








// What would be the result of the following statements?
const response = { 
  a: null, 
  b: { 
     x: "foo" 
  } 
};
const { 
  a = 10, 
  b: output 
} = response;








// What is the "?." called in here? What does it do?
if (a.b?.c?.d) {
  ..........
}






// What is the "??" operator called? What does it do?
const a = b ?? c;








// What would be the end result of the following?
const a = 10;
const b = 5;
const c = 20;
const d = (x) => x * 10;
const result = [a, b, c].map(d);