[30일코딩] 사칙연산과 논리연산

대수의 기본은 사칙연산 4개과 나머지(%) 이다.

나머지는 나중에 자알~ 활용하는 값이 있으므로 알아만 놓자.

그 외 논리연산자: 같음(등호), 같지않음(부등호), 큼/작음 등이있다.

컴퓨터는 1 or 0 이나 같다/같지않다와 같이 이분법적으로 값을 인식한다.

산술연산자 Arithmetic Operators

Arithmetic Operators 
The binary operators used for arithmetic are as follows:

• +: Additive
• -: Subtraction
• *: Multiplication
• /: Division
• %: Remainder (modulo)

논리연산자 Logical Operators

Additional Operators

• +: A binary operator used for String concatenation
• ++: This unary operator is used to preincrement (increment by 1 before use) when prepended to a variable name or postincrement (increment by 1 after use) when appended to a variable.
• --: This unary operator is used to predecrement (decrement by 1 before use) when prepended to a variable name or postdecrement (decrement by 1 after use) when appended to a variable.
• !: This unary operator means not (negation). It's used before a variable or logical expression that evaluates to true or false.
• ==: This binary operator is used to check the equality of 2 primitives.
• !=: This binary operator is used to check the inequality of 2 primitives.
• <, >, <=, >=: These are the respective binary operators for less than, greater than, less than or equal to, and greater than or equal to, and are used to compare two operands.
• &&, ||: These are the respective binary operators used to perform logical AND and logical OR operations on two boolean (i.e.: true or false) statements.
• ? : This ternary operator is used for simple conditional statements (i.e.: if ? then : else).

DataType  Casting

같은 숫자 int, double 끼리도 연산을 하다보면

가장 호환범위가 넓은 데이터타입 으로 데이터타입이 변동된다.

따라서 필요할 경우에는 연산결과의 데이터타입을 Casting (변환) 해야한다.

출처 | https://www.hackerrank.com/challenges/30-operators/tutorial