JVM ifeq(条件判断)

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public class Test {
    public static void main(String[] args) {
        int a = 0;
        if (a == 0) {
            a = 1314;
        }else{
            a = 520;
        }
    }
}

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/Library/Java/JavaVirtualMachines/jdk1.8.0_291.jdk/Contents/Home\bin\javap -v Test
Classfile /Users/baoguo/codes/demo/target/classes/Test.class
  Last modified Mar 26, 2022; size 465 bytes
  MD5 checksum a4dc32500b700c2496d8480e65e11b75
  Compiled from "Test.java"
public class Test
  minor version: 0
  major version: 52
  flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
   #1 = Methodref          #3.#21         // java/lang/Object."<init>":()V
   #2 = Class              #22            // Test
   #3 = Class              #23            // java/lang/Object
   #4 = Utf8               <init>
   #5 = Utf8               ()V
   #6 = Utf8               Code
   #7 = Utf8               LineNumberTable
   #8 = Utf8               LocalVariableTable
   #9 = Utf8               this
  #10 = Utf8               LTest;
  #11 = Utf8               main
  #12 = Utf8               ([Ljava/lang/String;)V
  #13 = Utf8               args
  #14 = Utf8               [Ljava/lang/String;
  #15 = Utf8               a
  #16 = Utf8               I
  #17 = Utf8               StackMapTable
  #18 = Utf8               MethodParameters
  #19 = Utf8               SourceFile
  #20 = Utf8               Test.java
  #21 = NameAndType        #4:#5          // "<init>":()V
  #22 = Utf8               Test
  #23 = Utf8               java/lang/Object
{
  public Test();
    descriptor: ()V
    flags: ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
         0: aload_0
         1: invokespecial #1                  // Method java/lang/Object."<init>":()V
         4: return
      LineNumberTable:
        line 1: 0
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       5     0  this   LTest;

  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=2, args_size=1
         0: iconst_0
         1: istore_1
         2: iload_1
         3: ifne          13  //与数字零做比较 如果是其他数字，则用if_icmpne 指令
         6: sipush        1314
         9: istore_1
        10: goto          17
        13: sipush        520
        16: istore_1
        17: return
      LineNumberTable:
        line 3: 0
        line 4: 2
        line 5: 6
        line 7: 13
        line 9: 17
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      18     0  args   [Ljava/lang/String;
            2      16     1     a   I
      StackMapTable: number_of_entries = 2
        frame_type = 252 /* append */
          offset_delta = 13
          locals = [ int ]
        frame_type = 3 /* same */
    MethodParameters:
      Name                           Flags
      args
}
SourceFile: "Test.java"

Process finished with exit code 0