if (var1) var2 = false
else var2 = true

var2 = !var1

private static boolean m1(boolean value) {
    boolean result;
    if (value) result = false;
    else result = true;

    return result;
}

private static boolean m2(boolean value) {
    boolean result = !value;
    return result;
}

private static boolean m1(boolean);
     0: iload_0
     1: ifeq          9
     4: iconst_0
     5: istore_1
     6: goto          11
     9: iconst_1
     10: istore_1
     11: iload_1
     12: ireturn

private static boolean m2(boolean);
     0: iload_0
     1: ifne
     4: iconst_1
     5: goto          9
     8: iconst_0
     9: istore_1
    10: iload_1
    11: ireturn

boolean result = !value

if (var1) var2 = false;
else var2 = true;

if (var1) var2 = false;
else var2 = true;
return var2;

var2 = !var1;

return !var1;

return  var2 = !var1;

return not var1;

return  var2 = not var1;

if ( bool var2 = not var1 )
{
    // using var2
}

while ( bool var2 = not var1 )
{
    //...
}

bool var2;

while ( var2 = !var1 )
{
   // changing of var1
}

test a
jz ZERO
jmp NONZERO
ZERO: mov b 1
jmp DONE
NONZERO: mov b 0
DONE: no

test a
jz ZERO
mov b 0
jmp DONE
ZERO: mov b 1
DONE: nop

xor b, b // то же, что `mov b 0`, но быстрее
test a
jnz NONZERO
mov b 1
NONZERO: nop

mov b a
xor b 1