65 lines
1.7 KiB
Java
65 lines
1.7 KiB
Java
public class Java34 {
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public static void main(String[] args) {
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int a = 1; // 기본자료형
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Integer b = new Integer(1); // 객체자료형
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System.out.println(a);
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System.out.println(b.intValue()); // 1
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System.out.println(b.toString()); // "1"
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System.out.println("=======================");
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int c = new Integer(1); // unboxing
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Integer d = 1; // boxing
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System.out.println(c);
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System.out.println(d.intValue()); // 1
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System.out.println(d.toString()); // "1"
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System.out.println("=======================");
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Object[] obj = new Object[3];
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obj[0] = new Integer(1);
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obj[1] = new Integer(2);
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obj[2] = new Integer(3);
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System.out.println(obj[0].toString());
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System.out.println(obj[1].toString());
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System.out.println(obj[2].toString());
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System.out.println("=======================");
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Object[] obj2 = new Object[3];
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obj2[0] = 1;
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obj2[1] = 2;
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obj2[2] = 3;
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System.out.println(obj2[0].toString());
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System.out.println(obj2[1].toString());
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System.out.println(obj2[2].toString());
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System.out.println("=======================");
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// "100" + "100" = 200
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String x = "100";
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String y = "100";
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System.out.println(x + y); // "100100"
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System.out.println("=======================");
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int i = Integer.parseInt(x);
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int j = Integer.parseInt(y);
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System.out.println(i + j); // 200
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System.out.println("=======================");
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// 100 + 100 = "100100"
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String v1 = String.valueOf(i);
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String v2 = String.valueOf(j);
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System.out.println(v1 + v2);
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}
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}
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