Tag: javascript coding questions

const data = {
    name: "javascript",
    name: "React"
}

const result = data.name.at(-2);

console.log(result);

Output:

c

• In JavaScript Objects if we have duplicate property names, only the last definition will be retained. So in this case data.name will be "React".
• .at(-2) will give the second character from the last which is ‘c’ in this case.

const obj1 = {a: 1, b: 2};
const obj2 = {c: 2, d:4, e:5};

Object.assign(obj2, obj1);

const result = Object.keys(obj2);

console.log(result)

Output:

[ 'c', 'd', 'e', 'a', 'b' ]

• Object.assign(obj2, obj1) : merges obj1 properties into obj2.( adding the properties from obj1 into obj2 directly.)
• Object.keys(obj2): Gets the keys of the modified obj2.
• Since obj1’s keys (a and b) are added to obj2, result includes all keys from both objects.

const expr1 = (null <= 0);
const expr2 = ('' == false);

const result = (expr1 === expr2);

console.log(result)

Output:

true

• expr1 = (null <= 0): In JavaScript, null is converted to ‘0’ when compared with number which makes null <= 0 evaluate to true.
• expr2 = ('' == false): The == operator performs type coercion. An empty string ('') is coerced to a number, which results in 0. Thus, '' == false evaluates to true because false is also coerced to 0.
• result = (expr1 === expr2): Since both expr1 and expr2 are true, the comparison true === true evaluates to true.