10 Things That I have learned During Problem Solving.

Today I learned this 10 things.

1) parseInt():

The parseInt() function parses a string and returns an integer.

const parsed = parseInt(x, base);

2) parseFloat()

The parseFloat() function parses an argument and returns a floating point number.

3) Factorial:

The factorial function says to multiply all whole numbers from our chosen number down to 1.

Examples:

4! = 4 × 3 × 2 × 1 = 24
7! = 7 × 6 × 5 × 4 × 3 × 2 × 1 = 5040
1! = 1

4) Recursive Method:

Recursive function is a function that call itself until it reaches a threshold value.

function factorial(n) {
if(n===0) return 1;
return n*factorial(n-1);
}

5) Math.PI :

The Math. PI is a property in JavaScript which is simply used to find the value of Pi i.e, in symbolic form Π which is nothing but it is the ratio of the circumference of a circle to its diameter, whose value is approximately 3.141

6) Multiple Switch:

We can define a singe scope for multiple cases if needed.

Example:

switch(condition) {
 case “a”:
 case “e”:
 case “i”:
 case “o”:
 case “u”:
 return “A”; 
 break;

7) Regular expressions:

Regular expressions are patterns used to match character combinations in strings. In JavaScript, regular expressions are also objects.

Example:

. => Find a single character, except newline or line terminator
\w => Find a word character
\W =>Find a non-word character
\d =>Find a digit
\D => Find a non-digit character
\s =>Find a whitespace character
\S =>Find a non-whitespace character
\b =>Find a match at the beginning/end of a word, beginning like this: \bHI, end like this: HI\b

8) readline():

Readline function is their method to read stdin and print() is the stdout method.

var name = readline();

9)Array.sort():

arr.sort() function is used to sort the array.

var nums =[2,9,3,8,9,8,6,4]
nums = nums.sort();
console.log(nums);
//output: [2,3,4,6,8,8,9,9]

10)throw():

The throw statement throws a user-defined exception.

Example:

if( conditions === true){
///execute this code
}
else{
throw(new Error(“error message”))
}

Thanks for reading.