generic argument java code example

Example 1: generic argument java

static void fromArrayToCollection(Object[] a, Collection c) {
    for (Object o : a) { 
        c.add(o); // compile-time error
    }
}

Example 2: java generics

// generic methods

public  List fromArrayToList(T[] a) {   
	    return Arrays.stream(a).collect(Collectors.toList());
	}

public static  List fromArrayToList(T[] a, Function mapperFunction) {
	    return Arrays.stream(a)
	      .map(mapperFunction)
	      .collect(Collectors.toList());
	}

// bounded generics

public  List fromArrayToList(T[] a) {
	    ...
	}

//multiple bounds



// upper bound wildcards

public static void paintAllBuildings(List buildings) {
	    ...
	}
    
// lower bound wildcard