Free JavaScript-Developer-I Exam Braindumps

Which code statement correctly retrieves and returns an object from localStorage?

1. A. const retrieveFromLocalStorage = () =>{return JSON.stringify(window.localStorage.getItem(storageKey));}
2. B. const retrieveFromLocalStorage = (storageKey) =>{ return window.localStorage.getItem(storageKey);}
3. C. const retrieveFromLocalStorage = (storageKey) =>{ returnJSON.parse(window.localStorage.getItem(storageKey));}
4. D. const retrieveFromLocalStorage = (storageKey) =>{ return window.localStorage[storageKey];}

Correct Answer: C

Which statement phrases successfully?

1. A. JSON.parse ( ‘ foo ’ );
2. B. JSON.parse ( “ foo ” );
3. C. JSON.parse( “ ‘ foo ’ ” );
4. D. JSON.parse(‘ “ foo ” ’);

Correct Answer: D

What are two unique features of functions defined with a fat arrow as compared to normal function definition?
Choose 2 answers

1. A. The function generated its own this making ituseful for separating the function’s scope from its enclosing scope.
2. B. The function receives an argument that is always in scope, called parentThis, which is the enclosing lexical scop
3. C. If the function has a single expression in the function body, the expression will be evaluated and implicit returned.
4. D. The function uses the this from the enclosing scope.

Correct Answer: AC

A developer needs to test this function:
01const sum3 = (arr) => (
02if (!arr.length) return 0,
03if (arr.length === 1) return arr[0],
04if (arr.length === 2) return arr[0]+ arr[1],
05 return arr[0] + arr[1] + arr[2],
06 );
Which two assert statements are valid tests for the function? Choose 2 answers

1. A. console.assert(sum3(1, ‘2’)) == 12);
2. B. console.assert(sum3(0)) == 0);
3. C. console.assert(sum3(-3, 2 )) == -1);
4. D. console.assert(sum3(‘hello’, 2, 3, 4)) === NaN);

Correct Answer: AC

Refer to code below:
Let productSKU = ‘8675309’ ;
A developer has a requirement to generate SKU numbers that are always 19 characters lon, starting with ‘sku’,and padded with zeros.
Which statement assigns the values sku0000000008675309 ?

1. A. productSKU = productSKU .padStart (19. ‘0’).padstart(‘sku’);
2. B. productSKU = productSKU .padEnd (16. ‘0’).padstart(‘sku’);
3. C. productSKU = productSKU .padEnd (16. ‘0’).padstart(19, ‘sku’);
4. D. productSKU = productSKU .padStart (16. ‘0’).padstart(19, ‘sku’);

Correct Answer: D