How condition variables work and store in memory in Java?

Question

//Case1
if(a > 5){
    //..
}

//Case2
private static final int NUM1 = 5;
if(a > NUM1){
    //..
}

/////////////////////////////////////////////

//Case3
if(a > 6 + b){
    //..
}

//Case4
private static final int NUM2 = 6;
if(a > NUM2  + b){
    //..
}

In Java
1. How if condition's variables work in java? (for example: if(a > 5) how 5 is stored in memory? like final or else?)
2. should i use case2 instead of case1 for more performance?
3. should i use case4 instead of case3 for more performance?

for(int i = 0; i < 1000000000; i++){
    if(a > 5){}
    if(a > NUM){}
    if(a > 6 + b){}
    if(a > NUM  + b){}
}

4. if i get into the loop, is result change?

Answer 1

I compiled code with these statements and disassembled.

As you can see, there is no difference for comparisons between integer literals, and comparisons for public static final primitives.

Curiously, on some JVMs the comparison (a>6+b) might be faster than (a>5), if bipush and iadd are more efficient than iconst. I'm personally not sure why bipush is used for cases 3 and 4 only. If someone could shed some light on this I would be interested.

// method 1; if(a>5)
  13: iload_1
  14: iconst_5
  15: if_icmple     25
  18: getstatic     #4                  // Field java/lang/System.out:Ljava/io/PrintStream;
  21: iconst_1
  22: invokevirtual #5                  // Method java/io/PrintStream.println:(I)V
// method 2; if(a>NUM1)
  25: iload_1
  26: iconst_5
  27: if_icmple     37
  30: getstatic     #4                  // Field java/lang/System.out:Ljava/io/PrintStream;
  33: iconst_2
  34: invokevirtual #5                  // Method java/io/PrintStream.println:(I)V
// method 3; if(a > 6+b)
  37: iload_1
  38: bipush        6
  40: iload_2
  41: iadd
  42: if_icmple     52
  45: getstatic     #4                  // Field java/lang/System.out:Ljava/io/PrintStream;
  48: iconst_1
  49: invokevirtual #5                  // Method java/io/PrintStream.println:(I)V
// method 4; if(a > 6+b)
  52: iload_1
  53: bipush        6
  55: iload_2
  56: iadd
  57: if_icmple     67
  60: getstatic     #4                  // Field java/lang/System.out:Ljava/io/PrintStream;
  63: iconst_1
  64: invokevirtual #5                  // Method java/io/PrintStream.println:(I)V
  67: return