javaのお勉強.String(equals, equalsIgnoreCase, ==)

equals は大文字小文字を区別して一致するか判定
equalsIgnoreCase 大文字小文字区別せずに判定
== は同じオブジェクトかどうかの判定

/*
a.equals(b) == true
a.equalsIgnoreCase(b) == true
(a == b) == true
*/
public class Test {
	public static void main(String[] args) {
		String a = "ABC";
		String b = "ABC";
		
		if(a.equals(b)) {
			System.out.println("a.equals(b) == true");
		} else {
			System.out.println("a.equals(b) == false");
		}

		if(a.equalsIgnoreCase(b)) {
			System.out.println("a.equalsIgnoreCase(b) == true");
		} else {
			System.out.println("a.equalsIgnoreCase(b) == false");
		}

		if(a == b) {
			System.out.println("(a == b) == true");
		} else {
			System.out.println("(a == b) == false");
		}
	}
}

/*
a.equals(b) == true
a.equalsIgnoreCase(b) == true
(a == b) == false
*/
public class Test {
	public static void main(String[] args) {
		String a = "ABC";
		String b = new String("ABC");
		
		if(a.equals(b)) {
			System.out.println("a.equals(b) == true");
		} else {
			System.out.println("a.equals(b) == false");
		}

		if(a.equalsIgnoreCase(b)) {
			System.out.println("a.equalsIgnoreCase(b) == true");
		} else {
			System.out.println("a.equalsIgnoreCase(b) == false");
		}

		if(a == b) {
			System.out.println("(a == b) == true");
		} else {
			System.out.println("(a == b) == false");
		}
	}
}

/*
a.equals(b) == false
a.equalsIgnoreCase(b) == true
*/
public class Test {
	public static void main(String[] args) {
		String a = "ABC";
		
		if(a.equals("abc")) {
			System.out.println("a.equals(b) == true");
		} else {
			System.out.println("a.equals(b) == false");
		}

		if(a.equalsIgnoreCase("abc")) {
			System.out.println("a.equalsIgnoreCase(b) == true");
		} else {
			System.out.println("a.equalsIgnoreCase(b) == false");
		}
	}
}