Ten Things A Serious JavaScript Developer Should Know

JavaScript is a high-level programming language that conforms to the ECMAScript specification. If you are a JavaScript developer, you must have to know about basic things in JavaScript.

If you are a Serious about JavaScript, Here ten things you must have to know:

1.charAt(): charAt() is a JavaScript String method that checks the position number of a character in a String. It takes input as an index number and find the character of that index position.

const sentence = ‘I am serious JavaScript Developer’;

const index = 5;

console.log(`The character at index ${index} is ${sentence.charAt(index)}`);

// expected output: “The character at index 5is s”

2. concat() : concat() is a JavaScript String method that concatenates string arguments and returns new string.

const str1 = ‘Java’;

const str2 = ‘Script’;

console.log(str1.concat(‘ ‘, str2));

//output: “Java Script”

3. includes(): includes() is a JavaScript String method which checks if there any string in another string and returns a boolean value.It is case sensitive.

const sentence = ‘I am a serious JavaScript Developer’;

const word = ‘JavaScript’;

console.log(`The word “${word}” ${sentence.includes(word) ? ‘is’ : ‘is not’} in the sentence`);

4. indexOf(): indexOf() is a JavaScript String method that returns the position value of a specified argument. In input if anyone provides a specified value then indexOf() return the position number of that value otherwise it returns -1.

const paragraph = ‘I am serious JavaScript Developer’;

const searchTerm = ‘JavaScript’;

const indexOfFirst = paragraph.indexOf(searchTerm);

console.log(`The index of the first “${searchTerm}” from the beginning is ${indexOfFirst}`);

// output: “The index of the first “JavaScript” from the beginning is 13"

5.lastIndexOf(): lastIndexOf() is a JavaScript String method that returns the position value of a specified argument searching from backwards.

6. trim(): trim() is a JavaScript String method which simple remove whitespace from both side of a string

const str = ‘ JavaScript ‘;

console.log(str);

// expected output: “JavaScript”;

7. isNaN(): isNaN() is a JavaScript method that check the input value is it is NaN and Number .

8. parseInt(): parseInt() is a JavaScript method that return any arguments value as integer number.

console.log(parseInt(‘100.50’));

//output: 100

9.parseFloat(): parseFloat() is a JavaScript method that return any arguments value as floating number and input is integer then return integer or return floating value

console.log(parseFloat(‘60.55’));

//output: 60.55

console.log(parseFloat(‘60’));

//output: 60

10. Math.abs(): Math.abs() is a JavaScript method that returns absulte value of input.

const number1 = -100

console.log(Math.abs(number1));

//output: 100

const number2 = 100

console.log(Math.abs(number2));

//output: 100