Java第十四天

Author: chao420456

day14/API要掌握的简化图解.bmp

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+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.7"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

day14/code/day14_BigInteger_BigDecimal/.classpath

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+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>day14_BigInteger_BigDecimal</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

day14/code/day14_BigInteger_BigDecimal/.project

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+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.7
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.7
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.7

day14/code/day14_BigInteger_BigDecimal/.settings/org.eclipse.jdt.core.prefs

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+package cn.itcast_01;
+
+import java.math.BigInteger;
+
+/*
+ * BigInteger:可以实现大整数的计算
+ * 构造方法：BigInteger(String val)
+ */
+public class BigIntegerDemo {
+	public static void main(String[] args) {
+		// System.out.println(Integer.MAX_VALUE); // 2147483647
+
+		// Integer i = new Integer("2147483648"); // NumberFormatException
+		// System.out.println(i);
+
+		BigInteger bi = new BigInteger("2147483648");
+		System.out.println(bi);
+	}
+}

day14/code/day14_BigInteger_BigDecimal/bin/cn/itcast_01/BigIntegerDemo.class

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+package cn.itcast_01;
+
+import java.math.BigInteger;
+
+public class BigIntegerDemo2 {
+	public static void main(String[] args) {
+		BigInteger bi1 = new BigInteger("20");
+		BigInteger bi2 = new BigInteger("10");
+
+		// public BigInteger add(BigInteger val)
+		System.out.println("add:" + bi1.add(bi2));
+
+		// public BigInteger subtract(BigInteger val)
+		System.out.println("subtract:" + bi1.subtract(bi2));
+
+		// public BigInteger multiply(BigInteger val)
+		System.out.println("multiply:" + bi1.multiply(bi2));
+
+		// public BigInteger divide(BigInteger val)
+		System.out.println("divide:" + bi1.divide(bi2));
+
+		// public BigInteger[] divideAndRemainder(BigInteger val)
+		BigInteger[] bis = bi1.divideAndRemainder(bi2);
+		for (int x = 0; x < bis.length; x++) {
+			System.out.println(bis[x]);
+		}
+
+	}
+}