Not really. Inside a struct, you can make use of bit fields. So if you know you’ll need a certain, fixed amount of entries, this would be a way to save a few bits (but note that the struct will always be padded to at least the next whole amount of bytes). Also note that … Read more
In which case should you use primitive types(int) or reference types (Integer)? As a rule of thumb, I will use a primitive (such as int) unless I have to use a class that wraps a primitive. One of the cases were one must use a wrapper class such as Integer is in the case of … Read more
This comparision between Java standard collections, Trove and Colt might be helpful.
In Java, integer literals are of type int by default. For some other types, you may suffix the literal with a case-insensitive letter like L, D, F to specify a long, double, or float, respectively. Note it is common practice to use uppercase letters for better readability. The Java Language Specification does not provide the … Read more
Yes, it’s valid – it will promote the int to a double before performing the comparison. See JLS section 15.20.1 (Numerical Comparison Operators) which links to JLS section 5.6.2 (Binary Numeric Promotion). From the latter: Widening primitive conversion (§5.1.2) is applied to convert either or both operands as specified by the following rules: If either … Read more
Both articles say that string is NOT a primitive type. Which it is not. If you compile and run the example code from the second article it would print: string is not a primitive type. I think the confusion about this is, that the syntax of of creating a new string is similar to creating … Read more
Try the following: int i = 20; float f = 20.2f; System.out.println(((Object)i).getClass().getName()); System.out.println(((Object)f).getClass().getName()); It will print: java.lang.Integer java.lang.Float As for instanceof, you could use its dynamic counterpart Class#isInstance: Integer.class.isInstance(20); // true Integer.class.isInstance(20f); // false Integer.class.isInstance(“s”); // false
You can use the property Type.IsPrimitive, but be carefull because there are some types that we can think that are primitives, but they aren´t, for example Decimal and String. Edit 1: Added sample code Here is a sample code: if (t.IsPrimitive || t == typeof(Decimal) || t == typeof(String) || … ) { // Is … Read more
Once again, Apache Commons Lang is your friend. They provide ArrayUtils.toPrimitive() which does exactly what you need. You can specify how you want to handle nulls.
Am I wrong in assuming it should be faster and more efficient? I’d hate to go through and change everything in a massive program to find out I wasted my time. Short answer Yes, you are wrong. In most cases, it makes little difference in terms of space used. It is not worth trying to … Read more