极客教程Java FloatBuffer compareTo()方法及示例
java.nio.FloatBuffer 类的 compareTo() 方法是用来比较一个缓冲区和另一个缓冲区。两个Float缓冲区通过比较它们的剩余元素序列进行比较，不考虑每个序列在其相应缓冲区中的起始位置。一对Float元素的比较是通过调用Float.compare(float, float)进行的，只是-0.0和0.0被认为是相等的。Float.NaN被该方法认为是等于自己，并且大于所有其他的浮点数（包括Float.POSITIVE_INFINITY）。Float缓冲区不能与任何其他类型的对象相提并论。语法 :
public int compareTo(FloatBuffer that)
参数： 该方法接受一个 floatbuffer对象 作为参数，该缓冲区将与之进行比较。
返回值： 该方法在该缓冲区小于、等于或大于给定的缓冲区时返回一个 负整数、零或正整数 。下面是说明compareTo()方法的例子：
例子1： 当两个FloatBuffer都相等时。
// Java program to demonstrate
// compareTo() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the fb
int capacity1 = 3;
// Creating the FloatBuffer
try {
// creating object of floatbuffer fb
// and allocating size capacity
FloatBuffer fb = FloatBuffer.allocate(capacity1);
// putting the value in fb
fb.put(9.56F);
fb.put(7.61F);
fb.put(4.61F);
// rewind the float buffer
fb.rewind();
// print the FloatBuffer
System.out.println("FloatBuffer fb: "
+ Arrays.toString(fb.array()));
// creating object of floatbuffer fb1
// and allocating size capacity
FloatBuffer fb1 = FloatBuffer.allocate(capacity1);
// putting the value in fb1
fb1.put(9.56F);
fb1.put(7.61F);
fb1.put(4.61F);
// rewind the float buffer
fb1.rewind();
// print the FloatBuffer
System.out.println("FloatBuffer fb1: "
+ Arrays.toString(fb1.array()));
// compare both buffer and store the value into integer
int i = fb.compareTo(fb1);
// if else condition
if (i == 0)
System.out.println("\nboth buffer are lexicographically equal");
else if (i >= 0)
System.out.println("\nfb is lexicographically greater than fb1");
else
System.out.println("\nfb is lexicographically less than fb1");
}
catch (IllegalArgumentException e) {
System.out.println("Exception throws : " + e);
}
catch (ReadOnlyBufferException e) {
System.out.println("Exception throws : " + e);
}
}
}
输出
FloatBuffer fb: [9.56, 7.61, 4.61]
FloatBuffer fb1: [9.56, 7.61, 4.61]
both buffer are lexicographically equal
例2： 当这个FloatBuffer大于传递的FloatBuffer时
// Java program to demonstrate
// compareTo() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the fb
int capacity1 = 3;
// Creating the FloatBuffer
try {
// creating object of floatbuffer fb
// and allocating size capacity
FloatBuffer fb = FloatBuffer.allocate(capacity1);
// putting the value in fb
fb.put(9.56F);
fb.put(7.61F);
fb.put(4.61F);
// rewind the float buffer
fb.rewind();
// print the FloatBuffer
System.out.println("FloatBuffer fb: "
+ Arrays.toString(fb.array()));
// creating object of floatbuffer fb1
// and allocating size capacity
FloatBuffer fb1 = FloatBuffer.allocate(capacity1);
// putting the value in fb1
fb1.put(8.56F);
fb1.put(7.61F);
fb1.put(4.61F);
// rewind the float buffer
fb1.rewind();
// print the FloatBuffer
System.out.println("FloatBuffer fb1: "
+ Arrays.toString(fb1.array()));
// compare both buffer and store the value into integer
int i = fb.compareTo(fb1);
// if else condition
if (i == 0)
System.out.println("\nboth buffer are lexicographically equal");
else if (i >= 0)
System.out.println("\nfb is lexicographically greater than fb1");
else
System.out.println("\nfb is lexicographically less than fb1");
}
catch (IllegalArgumentException e) {
System.out.println("Exception throws : " + e);
}
catch (ReadOnlyBufferException e) {
System.out.println("Exception throws : " + e);
}
}
}
输出
FloatBuffer fb: [9.56, 7.61, 4.61]
FloatBuffer fb1: [8.56, 7.61, 4.61]
fb is lexicographically greater than fb1
例3： 当这个FloatBuffer小于传递的FloatBuffer时
// Java program to demonstrate
// compareTo() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the fb
int capacity1 = 3;
// Creating the FloatBuffer
try {
// creating object of floatbuffer fb
// and allocating size capacity
FloatBuffer fb = FloatBuffer.allocate(capacity1);
// putting the value in fb
fb.put(8.56F);
fb.put(7.61F);
fb.put(4.61F);
// rewind the float buffer
fb.rewind();
// print the FloatBuffer
System.out.println("FloatBuffer fb: "
+ Arrays.toString(fb.array()));
// creating object of floatbuffer fb1
// and allocating size capacity
FloatBuffer fb1 = FloatBuffer.allocate(capacity1);
// putting the value in fb1
fb1.put(9.56F);
fb1.put(7.61F);
fb1.put(4.61F);
// rewind the float buffer
fb1.rewind();
// print the FloatBuffer
System.out.println("FloatBuffer fb1: "
+ Arrays.toString(fb1.array()));
// compare both buffer and store the value into integer
int i = fb.compareTo(fb1);
// if else condition
if (i == 0)
System.out.println("\nboth buffer are lexicographically equal");
else if (i >= 0)
System.out.println("\nfb is lexicographically greater than fb1");
else
System.out.println("\nfb is lexicographically less than fb1");
}
catch (IllegalArgumentException e) {
System.out.println("Exception throws : " + e);
}
catch (ReadOnlyBufferException e) {
System.out.println("Exception throws : " + e);
}
}
}
输出
FloatBuffer fb: [8.56, 7.61, 4.61]
FloatBuffer fb1: [9.56, 7.61, 4.61]
fb is lexicographically less than fb1