자바/java 제어문 - 조건문 if, else

if(조건식){}

if(a >= 50 && a <= 100) {
	System.out.println("hello~");
}

if(조건식){}else{}

if(age >= 20) {
		System.out.println("성인");
} else {
		System.out.println("미성인");
}

if(조건식){}else if(){}

/* if(조건식1){실행구문1}
	 else if(조건식2){실행구문2}
	 else if(조건식2){실행구문3}
		...
	 else{기본실행구문} 필수아님 */

if (score >= 90) {
		grade = 'A';
}
else if (score >= 80) {
		grade = 'B';
}
else if (score >= 70) {
		grade = 'C';
}
else if (score >= 60) {
		grade = 'D';
}
else {
		grade = 'F';
}

중첩된 if문

if(score >= 90) {
		grade = "A";
		if(score >= 95) {
				grade += "+"; // grade = grade + "+"
		}
}
else if(score >= 80) {
		grade = "B";
		if(score >= 85) {
				grade += "+";
		}
}