Salesforce JavaScript-Developer-I 問題集

質問 1：
Which two console logs output NaN?
Choose 2 answers | |
A. console.loeg(10 / 'five');
B. console.log(parseInt ' ("two')) ;
C. console.log(10 / 0);
D. console.log(10 / Number('5) ) ;
正解：B,D

質問 2：
Refer to thefollowing code that imports a module named utils:
import (foo, bar) from '/path/Utils.js';
foo() ;
bar() ;
Which two implementations of Utils.js export foo and bar such that the code above runs without error?
Choose 2 answers
A. Export default class {foo() { return 'foo' ; }bar() { return 'bar' ; }}
B. // FooUtils.js and BarUtils.js existImport (foo) from '/path/FooUtils.js';Import (boo) from '
/path/NarUtils.js';
C. const foo = () => { return 'foo' ; }const bar = () => { return 'bar' ; }export { bar, foo }
D. const foo = () => { return 'foo';}const bar = () => {return 'bar'; }Export default foo, bar;
正解：A,C

質問 3：
A developer wants to iterate through an array of objects and count the objects and count the objects whose property value, name, starts with the letterN.
Const arrObj = [{"name" : "Zach"} , {"name" : "Kate"},{"name" : "Alise"},{"name" : "Bob"},{"name" :
"Natham"},{"name" : "nathaniel"}
Refer to the code snippet below:
01 arrObj.reduce(( acc, curr) => {
02 //missing line 02
02 //missing line 03
04 ). 0);
Which missing lines 02 and 03 return the correct count?
A. Const sum = curr.startsWith('N') ? 1: 0;Return acc +sum
B. Const sum = curr.startsWIth('N') ? 1: 0;Return curr+ sum
C. Const sum =curr.name.startsWIth('N') ? 1: 0;Return curr+ sum
D. Const sum = curr.name.startsWith('N') ? 1: 0;Return acc +sum
正解：D

質問 4：
Refer to the code below:
let o = {
get js() {
let city1 = String("st. Louis");
let city2 = String(" New York");
return {
firstCity: city1.toLowerCase(),
secondCity: city2.toLowerCase(),
}
}
}
What value can a developer expect when referencing o.js.secondCity?
A. An error
B. ' new york '
C. ' New York '
D. Undefined
正解：B

質問 5：
Refer to the followingcode:

A. Outer message
Inner message
B. Button message
C. Inner message
Outer message
D. Outer message
正解：B

質問 6：
Refer to code below:
Let a ='a';
Let b;
// b = a;
console.log(b);
What is displayed when the code executes?
A. A
B. Null
C. ReferenceError: b is not defined
D. Undefined
正解：D

質問 7：
Refer to the code below:
letsayHello = () => {
console.log ('Hello, world!');
};
Which code executes sayHello once, two minutes from now?
A. setTimeout(sayHello, 12000);
B. setInterval(sayHello, 12000);
C. setTimeout(sayHello(), 12000);
D. delay(sayHello, 12000);
正解：A

質問 8：
There is a new requirement for a developer to implement a currPrice method that will return the current price of the item or sales..

What is the output when executing the code above
A. 508072
B. 5080Uncaught ReferenceError:this,discount is undefined72
C. 50805072
D. 50Uncaught TypeError: saleItem,desrcription is not a function5080
正解：C

質問 9：
Refer to the code snippet below:
Let array = [1, 2, 3, 4, 4, 5, 4, 4];
For (let i =0; i <array.length; i++){
if (array[i] === 4) {
array.splice(i, 1);
}
}
What is the value of the array after the code executes?
A. [1, 2, 3, 4, 5, 4]
B. [1, 2, 3, 4, 5, 4, 4]
C. [1, 2, 3, 4, 4, 5, 4]
D. [1, 2, 3, 5]
正解：A