Learn about various methods to remove the last character from the string in JavaScript, including slice, substring, and the replace method.

Understand what are optional parameters in JavaScript, its use cases, and different methods to declare it.

Learn some simple methods to clear or empty an array in javascript using pop, and splice functions or by re-assigning or modifying the array.

Understand what are undefined variables and how to check for undefined in JavaScript using various methods.

Learn everything about string interpolation and template literals in JavaScript, along with its various use cases.

Understand everything about the NaN property in JavaScript and how to handle it in different mathematical operations along with examples.

Learn everything about findIndex() Method for Arrays in JavaScript and how to use in different situations.

Understand everything about the startsWith() method in JavaScript to check if a string starts with a certain string.

Understand the key differences between let and var keywords in JavaScript, based on scope, redeclaration, and hoisting.

Understand error handling in JavaScript using try-catch and how to throw custom errors with throw statement using different examples.