---
tags: Educative
---

# Become a Spring Boot Developer

## Module 1: Core Java Concepts

### Variable and User Input

User input example code:

import java.util.Scanner;

class take_input {
    public static void main(String[] args) {
        Scanner scanner_one = new Scanner(System.in);
        System.out.println("Enter your name: ");
        String name = scanner_one.nextLine();
        System.out.println("Your name is: " + name);
    }
}

### Simple Math Logic

#### Operator associativity
Operator associativity determines whether, in an expression, if there are multiple operators like (1 + 2 - 5), how will they be evaluated if they are of the same precedence.

Operators | Description | Associativity
|--|--|--|
|+ , - | Unary Plus and minus |Right to left|
|! , ~ |Logical NOT and bitwise NOT |Right to left
|= |Direct assignment |Right to left
|+= , -= |Assignment by sum and difference |Right to left
|*= , /= , %=| Assignment by product, quotient, and remainder |Right to left
|  <<= , >>= |Assignment by bitwise left shift and right shift |Right to left
| &= , ^= , = |Assignment by bitwise AND, XOR, and OR |Right to left
| ++ , -- |Suffix/postfix increment and decrement |Right to left
| * , / , % vMultiplication, division, and remainder |Left to Right
|+ , - |Addition and subtraction |Left to Right
|<< , >> |Bitwise left shift and right shift |Left to Right
|< , <= |For relational operators |Left to Right
|> , >= |For relational operators |Left to Right
|== , != |For relational |Left to Right
|& |Bitwise AND| Left to Right
|^ |Bitwise XOR (exclusive or) |Left to Right
|&& |Logical AND Left to Right
| | Logical OR |Left to Right
| | Bitwise OR (inclusive or) |Left to Right

### Exponentiation

System.out.println("2 raised to the power 3 is " + Math.pow(2, 3));
System.out.println("Exponent squared is " + Math.exp(2));
System.out.println("The square root of 16 is " + Math.sqrt(16));
System.out.println("The cube root of 27 is " + Math.cbrt(27));

// 2 raised to the power 3 is 8.0
// Exponent squared is 7.38905609893065
// The square root of 16 is 4.0
// The cube root of 27 is 3.0

System.out.println("log of 2 is " + Math.log(2));
System.out.println("log to the base 10 of 100 is " + Math.log10(100));

System.out.println("tan(45) =" + Math.tan(Math.toRadians(45)));
System.out.println("sin(45) =" + Math.sin(Math.toRadians(45)));
System.out.println("cos(45) =" + Math.cos(Math.toRadians(45)));

System.out.println("Absolute value of -2: " + Math.abs(-2));

System.out.println("Maximum between 2.04 and 2.05: " + Math.max(2.04, 2.05));
System.out.println("Minimum between 2 and 23: " + Math.min(2, 23));


### String

str1.equals(str2);
str.split("");

String choice = "CoffeeOrTea";
//First: Only one argument
System.out.println(choice.substring(8)); //Tea
//Second: Two arguments
System.out.println(choice.substring(0, 6)); //Coffee