Namaste, In this blog I will discuss 10 code scenarios on Javascript .
function fx() {
return new Promise(resolve => {
setTimeout(() => {
resolve(‘resolved’);
}, 1000);
});
}
async function asyncFx() {
const result = await fx();
console.log(result);
}
asyncFx();
a.resolved
b.reject
c.undefined
d.error
e.null
Answer:a
Reason:The promise is successfully completed.
function fx() {
return new Promise((resolve,reject) => {
setTimeout(() => {
reject(‘resolved’);
}, 1000);
});
}
async function asyncFx() {
const result = await fx();
console.log(result);
}
asyncFx();
a.reject
b.error
c.resolve
d.undefined
e.null
Answer:b
Reason:The program gives an error.
async function getData() {
try {
let response = await fetch(“jsontest.com/key/value”);
let data = await response.json();
console.log(data);
}catch (err) {
console.log(“problem”);
}
}
getData();
a.problem
b.{key:value}
c.json
d.undefined
e.null
Answer:a
Reason:The incorrect url yields into an error.
let city = {
“delhi”:1000,
};
console.log(Object.entries(city));
a. [ ‘delhi’, 1000 ]
b. { ‘delhi’, 1000 }
c. error
d. [ [ ‘delhi’, 1000 ] ]
e. ‘delhi’, 1000
Answer:d
Reason:The output is [ [ ‘delhi’, 1000 ] ].
let city = {
“delhi”:1000,
};
for (let [k,v] of Object.entries(city))
console.log(k,v);
a.[ ‘delhi’, 1000 ]
b. { ‘delhi’, 1000 }
c. error
d. [ [ ‘delhi’, 1000 ] ]
e. ‘delhi’, 1000
Answer:e
Reason:Individual values are extracted and printed.
let city = {
“mumbai”:2000,
“bangalore”:1500
};
console.log(Object.values(city));
a.[2000,1500]
b.[2000]
c.[1500]
d.[mumbai:2000]
e.[bangalore:1500]
Answer:a
Reason:The values() function only extracts the values.
let city = {
“mumbai”:2000,
“bangalore”:1500
};
let sum=0;
for (let obj of Object.values(city)) {
sum = obj + sum;
}
console.log(sum);
a.error
b.undefined
c.3500
d.2000
e.1500
Answer:c
Reason:The values are summed up.
let city = {
“delhi”:1000,
};
let obj = Object.getOwnPropertyDescriptors(city);
console.log(obj.enumerable, obj.delhi.enumerable);
a.true
b.false
c.delhi
d.1000
e.error
Answer:a
Reason:The enumerable is true by default.
async function getData() {
try {
let response = await fetch(“http://echo.jsontest.com/key/value”);
let data = await response.json();
console.log(data);
}catch (err) {
console.log(“error “);
}
}
getData();
a.{key:value}
b.error
c.echo
d.undefined
e.10
Answer:a
Reason:The value returned is {key:value}.
function fx() {
return new Promise((resolve,reject) => {
setTimeout(() => {
reject(‘resolved’);
}, 1000);
});
}
async function asyncFx() {
try {
const result = await fx();
}catch (err) {
console.log(err);
}
}
asyncFx();
a.resolved
b.reject
c.error
d.undefined
e.null
Answer:a
Reason:When error occurs catch block is called and prints resolved.
Source: hashnode.com