JavaScript: Methods

Question 1

What is sort() method?
What is the syntax?

Answer 1

const comparisonOperators = [“Equal”, “Not Equal”, “Strict Equal”, “Strict Not Equal”, “Greater Than”, “Less Than”];
const arithmeticOperators = [”+”, “-“, “%”];
const logicalOperators = [“and”, “or”, “not”];
const myString = “Hello String”;
const numString = “1234”;
…
The sort() method of Array instances sorts the elements of an array in place and returns the reference to the same array, now sorted. The default sort order is ascending.

// Sorts comparisonOperators array and returns the sorted array
comparisonOperators.sort();

// Logs sorted array
console.log(comparisonOperators);

Question 2

What is the push() method?
What is the syntax?

Answer 2

const comparisonOperators = [“Equal”, “Not Equal”, “Strict Equal”, “Strict Not Equal”, “Greater Than”, “Less Than”];
const arithmeticOperators = [”+”, “-“, “%”];
const logicalOperators = [“and”, “or”, “not”];
const myString = “Hello String”;
const numString = “1234”;
…
// Adds elements to end of an array. Takes in at least one parameter
arithmeticOperators.push(“%”);

// Logs array with element “%” added to end
console.log(arithmeticOperators);

Question 3

What is the slice() method?
What is the syntax?

Answer 3

const comparisonOperators = [“Equal”, “Not Equal”, “Strict Equal”, “Strict Not Equal”, “Greater Than”, “Less Than”];
const arithmeticOperators = [”+”, “-“, “%”];
const logicalOperators = [“and”, “or”, “not”];
const myString = “Hello String”;
const numString = “1234”;
…
// Returns selected elements as a new array.
const logicalOperatorsSliced = logicalOperators.slice(0,2);

// Logs new array
console.log(logicalOperatorsSliced);

// The original array is unchanged
console.log(logicalOperators);

Question 4

What is the replace() method?
What is the syntax?

Answer 4

const comparisonOperators = [“Equal”, “Not Equal”, “Strict Equal”, “Strict Not Equal”, “Greater Than”, “Less Than”];
const arithmeticOperators = [”+”, “-“, “%”];
const logicalOperators = [“and”, “or”, “not”];
const myString = “Hello String”;
const numString = “1234”;
…
// Replaces “String” with “World” and returns new string
const myNewString = myString.replace(“String”, “World”);
console.log(myNewString);

// The original string is unchanged
console.log(myString);

Question 5

What is the parseInt method?

Answer 5

const comparisonOperators = [“Equal”, “Not Equal”, “Strict Equal”, “Strict Not Equal”, “Greater Than”, “Less Than”];
const arithmeticOperators = [”+”, “-“, “%”];
const logicalOperators = [“and”, “or”, “not”];
const myString = “Hello String”;
const numString = “1234”;
…
// parseInt is a built in method that will convert a string into an integer:
const convertedNum = parseInt(numString);
// logs number
console.log(typeof convertedNum);
// the original string is unchanged
console.log(numString)