underflow

问题 We know that Java does not handle underflows and overflows, but how does Javascript handle these for integers? Does it go back to a minimum/maximum? If yes, which minimum/maximum? I need to split a string and compute a hash value based on its characters. 回答1: In a simple test, when I try this: var max = Number.MAX_VALUE; var x = max + 10; var min = Number.MIN_VALUE; var y = min / 10; I find that x and max have the same value (in Chrome, IE and Firefox) so it appears that some overflows are

问题 Is there a general way to check for an overflow or an underflow of a given data type (uint32, int etc.)? I am doing something like this: uint32 a,b,c; ... //initialize a,b,c if(b < c) { a -= (c - b) } When I print a after some iterations, it displays a large number like: 4294963846. 回答1: To check for over/underflow in arithmetic check the result compared to the original values. uint32 a,b; //assign values uint32 result = a + b; if (result < a) { //Overflow } For your specific the check would

问题 I have read in many places that unsigned integer overflow is well-defined in C unlike the signed counterpart. Is underflow the same? For example: unsigned int x = -1; // Does x == UINT_MAX? Thanks. I can\'t recall where, but i read somewhere that arithmetic on unsigned integral types is modular, so if that were the case then -1 == UINT_MAX mod (UINT_MAX+1). 回答1: §6.2.5, paragraph 9: A computation involving unsigned operands can never overflow, because a result that cannot be represented by