comparison

来源： https://stackoverflow.com/questions/60741637/comparing-two-groups-with-multiple-variables-using-anova-or-another-testing-meth

来源： https://stackoverflow.com/questions/63699669/r-compare-all-elements-in-a-dataframe-column-with-an-element-in-a-row-in-anoth

来源： https://stackoverflow.com/questions/63699669/r-compare-all-elements-in-a-dataframe-column-with-an-element-in-a-row-in-anoth

来源： https://stackoverflow.com/questions/63699669/r-compare-all-elements-in-a-dataframe-column-with-an-element-in-a-row-in-anoth

来源： https://stackoverflow.com/questions/63699669/r-compare-all-elements-in-a-dataframe-column-with-an-element-in-a-row-in-anoth

来源： https://stackoverflow.com/questions/29672847/how-to-compare-contents-of-javascript-array-but-not-the-order-of-them

来源： https://stackoverflow.com/questions/44574679/python-deprecationwarning-elementwise-comparison-failed-this-will-raise-an

来源： https://stackoverflow.com/questions/44574679/python-deprecationwarning-elementwise-comparison-failed-this-will-raise-an

问题 Motivated by this question, I compared three different functions for checking if 8 bytes pointed to by the argument are zeros (note that in the original question, characters are compared with '0' , not 0 ): bool f1(const char *ptr) { for (int i = 0; i < 8; i++) if (ptr[i]) return false; return true; } bool f2(const char *ptr) { bool res = true; for (int i = 0; i < 8; i++) res &= (ptr[i] == 0); return res; } bool f3(const char *ptr) { static const char tmp[8]{}; return !std::memcmp(ptr, tmp, 8

问题 Motivated by this question, I compared three different functions for checking if 8 bytes pointed to by the argument are zeros (note that in the original question, characters are compared with '0' , not 0 ): bool f1(const char *ptr) { for (int i = 0; i < 8; i++) if (ptr[i]) return false; return true; } bool f2(const char *ptr) { bool res = true; for (int i = 0; i < 8; i++) res &= (ptr[i] == 0); return res; } bool f3(const char *ptr) { static const char tmp[8]{}; return !std::memcmp(ptr, tmp, 8