Java 8 function that always return the same value without regarding to parameter

Question

Is there a predefined Function in Java 8 that does something like this: ``` static Function constant(R val) { return (T t) -> { return val; }; } ``` To answer people's query on why I need this function here is the real usage when I am trying to parse an integer to an roman numerals: ``` // returns the stream of roman numeral symbol based // on the digit (n) and the exponent (of 10) private static Stream parseDigit(int n, int exp) { if (n < 1) return Stream.empty(); Symbol base = Symbol.base(exp); if (n < 4) { return IntStream.range(0, n).mapToObj(i -> base); } else if (n == 4) { return Stream.of(base, Symbol.fifth(exp)); } else if (n < 9) { return Stream.concat(Stream.of(Symbol.fifth(exp)), IntStream.range(5, n).mapToObj(i -> base)); } else { // n == 9 as n always < 10 return Stream.of(base, Symbol.base(exp + 1)); } } ``` And I guess the `IntStream.range(0, n).mapToObj(i -> base)` could be simplified to something like `Stream.of(base).times(n - 1)`, unfortunately…

Accepted Answer

A simple lambda, `x -> val` seems to be equivalent to your method; ``` Function test1 = constant(5); Function test2 = x -> 5; ``` ...both ignore the input and output the constant 5 when applied; ``` > System.out.println(test1.apply(2)); 5 > System.out.println(test2.apply(2)); 5 ```

Java 8 function that always return the same value without regarding to parameter

Solution

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