On the fact that lambda expressions cannot handle recursion

Why? lambda Expressions can't handle recursion ？ because lambda The expression itself is a way to write anonymous functions , When the function name is omitted , It is more difficult to call yourself .
The reflection mechanism can be used to obtain Method Object recursively calls itself , But it's not necessary to be complicated .

When we want to solve a problem by recursion and don't want to write a separate method , We can use functional programming , but lambda Recursion of expression is troublesome , So we don't have to lambda The expression , While using lambda Degenerate version of expression - Anonymous inner class .

As shown in the following code , Use anonymous inner classes to compute factorials .

java.util.function.Function<Integer,Integer> func = new java.util.function.Function<Integer, Integer>(){
    
    @Override
    public Integer apply(Integer a) {
    
        if(a==1){
    
            return 1;
        }
        return a*apply(a-1);
    }
};
System.out.println(func.apply(5));