- Primitive values
- Objects (collection of properties)
A falsy value is a value that is considered false when encountered in a Boolean context.
|false||The keyword false|
|0||The Number zero|
|-0||The Number negative zero|
|0n||The BigInt zero|
|“”, ”,“||Empty string value|
|null||null – the absence of any value|
|undefined||undefined – the primitive value|
|NaN||NaN – not a number|
Q3. Explain Type Coercion.
Type coercion is the automatic or implicit conversion of values from one data type to another (such as strings to numbers). Type conversion is similar to type coercion because they both convert values from one data type to another with one key difference — type coercion is implicit whereas type conversion can be either implicit or explicit.
const value1 = '1'; const value2 = 2; let sum = value1 + value2; console.log(sum);
- var – Declares a variable, optionally initializing it to a value.
- let – Declares a block scope local variable, optionally initializing it to a value.
- const – Declares a read-only named constant.
do...while– Creates a loop that executes a specified statement until the test condition evaluates to false. The condition is evaluated after executing the statement, resulting in the specified statement executing at least once.
for– Creates a loop that consists of three optional expressions, enclosed in parentheses and separated by semicolons, followed by a statement executed in the loop.
for...in– Iterates over the enumerable properties of an object, in arbitrary order. For each distinct property, statements can be executed.
for...of– Iterates over iterable objects (including arrays, array-like objects, iterators and generators), invoking a custom iteration hook with statements to be executed for the value of each distinct property.
for await...of– Iterates over async iterable objects, array-like objects, iterators and generators, invoking a custom iteration hook with statements to be executed for the value of each distinct property.
while– Creates a loop that executes a specified statement as long as the test condition evaluates to true. The condition is evaluated before executing the statement.
Block – A block statement is used to group zero or more statements. The block is delimited by a pair of curly brackets.
break – Terminates the current loop, switch, or label statement and transfers program control to the statement following the terminated statement.
continue – Terminates execution of the statements in the current iteration of the current or labeled loop, and continues execution of the loop with the next iteration.
if...else – Executes a statement if a specified condition is true. If the condition is false, another statement can be executed.
switch – Evaluates an expression, matching the expression’s value to a case clause, and executes statements associated with that case.
throw – Throws a user-defined exception.
try...catch – Marks a block of statements to try, and specifies a response, should an exception be thrown.