long-integer

I want to convert a hex string to long in java. I have tried with general conversion. String s = "4d0d08ada45f9dde1e99cad9"; long l = Long.valueOf(s).longValue(); System.out.println(l); String ls = Long.toString(l); But I am getting this error message: java.lang.NumberFormatException: For input string: "4d0d08ada45f9dde1e99cad9" Is there any way to convert String to long in java? Or am i trying which is not really possible!! Thanks! Long.decode(str) accepts a variety of formats: Accepts decimal, hexadecimal, and octal numbers given by the following grammar: DecodableString: Sign opt

By my reading of the C++ Standard, I have always understood that the sizes of the integral fundamental types in C++ were as follows: sizeof(char) <= sizeof(short int) <= sizeof(int) <= sizeof(long int) I deduced this from 3.9.1/2: There are four signed integer types: “signed char”, “short int”, “int”, and “long int.” In this list, each type provides at least as much storage as those preceding it in the list. Plain ints have the natural size suggested by the architecture of the execution environment Further, the size of char is described by 3.9.1/ as being: [...] large enough to store any

I am trying this code on GNU's C++ compiler and am unable to understand its behaviour: #include <stdio.h>; int main() { int num1 = 1000000000; long num2 = 1000000000; long long num3; //num3 = 100000000000; long long num4 = ~0; printf("%u %u %u", sizeof(num1), sizeof(num2), sizeof(num3)); printf("%d %ld %lld %llu", num1, num2, num3, num4); return 0; } When I uncomment the commented line, the code doesn't compile and is giving an error: error: integer constant is too large for long type But, if the code is compiled as it is and is executed, it produces values much larger than 10000000000. Why?

I want to handle the special case where multiplying two numbers together causes an overflow. The code looks something like this: int a = 20; long b = 30; // if a or b are big enough, this result will silently overflow long c = a * b; That's a simplified version. In the real program a and b are sourced elsewhere at runtime. What I want to achieve is something like this: long c; if (a * b will overflow) { c = Long.MAX_VALUE; } else { c = a * b; } How do you suggest I best code this? Update: a and b are always non-negative in my scenario. Java 8 has Math.multiplyExact , Math.addExact etc. for