Лекция 3 2017 Динамическая память, указатели на функции, символы, строки (с заметками) (Лекции (2017))

ࡏфӐӌӍҺӝ ӎӏӍһӏҸӋӋӄӏӍҺҸӌӄӨсҿӈӗӄӨ ॏ ߟࡈ ߝߢ ӋҸӏӑҸ ߞߜߝߣ һࡏࡏhttp://xkcd.ru/371ࡏࡏщӈҸӃҸӑҿӊӄ ࡫ӎӏӍҾӍӊӂҿӌӄҿ࡬ࡏࡏࡏщӈҸӃҸӑҿӊӛࡈ ӌӄӈӒҾҸ ӌҿ ӒӈҸӃӝҺҸӧәӄӅэӄӐӊҿӌӌӍҿ ӃӌҸӖҿӌӄҿ ŸĆ ࣌࣌ ߜࡏNULL ࡴ ӐӎҿӗӄҸӊӛӌӍҿ ӈӍӌӐӑҸӌӑӌӍҿ ӃӌҸӖҿӌӄҿࡈ ӐӄӋҺӍӊӄӃӄӏӒӧәҿҿࡈ ӖӑӍӒӈҸӃҸӑҿӊӛ ӌҿ ӒӈҸӃӝҺҸҿӑ ӌӄ ӌҸ ӈҸӈӒӧ ӎҸӋӨӑӛࡏ фҹӜӨҺӊҿӌӍ Һ ӃҸһӍӊӍҺӍӖӌӍӋӔҸӅӊҿ stdlib.hࡏint* ptr = NULL;int value = *ptr; // run time error*ptr = 37; // run time errorцҸӃӌӝҿ ӌҸӃҺҸӌӄӨࡈ ӌӍ ӐӒӑӛ ӍҾӌҸ ࡫ɯƚǃȒƚȘɾŏɾǞȩȘ ǀŏʕȀɾࡈ ɯƚǃǀŏʕȀɾࡈ ŏżżƚɯɯ ʲǞȩȀŏɾǞȩȘࡈࢀхӏӍһӏҸӋӋҸ ҺӝӎӍӊӌӄӊҸ ӌҿҾӍӎӒӐӑӄӋӒӧ ӍӎҿӏҸӗӄӧࡊࢁࡈ ࡊ࡬ࡏߟࡏࡏщӈҸӃҸӑҿӊӛࡈ ӒӈҸӃӝҺҸӧәӄӅ ӕӍӑӛ ӈӒҾҸщӈҸӃҸӑҿӊӛ ӑӏҸӈӑӒҿӑ ӒӈҸӃӝҺҸҿӋӍҿ ӐӍҾҿӏӂӄӋӍҿ ӈҸӈ ǞȘɾࡈ ӕӍӑӨ ӌҸӐҸӋӍӋ Ҿҿӊҿ ӑҸӋ ӌҸӕӍҾӄӑӐӨ ƇȩʕųȀƚ ࡴ ӢӑӍ ӎӍӑҿӌӗӄҸӊӛӌҸӨ ӍӘӄҹӈҸࡏvoid* ࡴ ӐӎҿӗӄҸӊӛӌӝӅ ӑӄӎ ӒӈҸӃҸӑҿӊӨࡈ ӈӍӑӍӏӝӅ ӋӍӂҿӑ ӒӈҸӃӝҺҸӑӛ ӌҸ ӊӧҹӝҿҾҸӌӌӝҿ Һ ӎҸӋӨӑӄࡏ тӍӂҿӑ ҹӝӑӛ ӎӏӄҺҿҾҿӌ ӈ ӊӧҹӍӋӒ ҾӏӒһӍӋӒ ӑӄӎӒ ӒӈҸӃҸӑҿӊҿӅ ӄӍҹӏҸӑӌӍࡏфҹӨӃҸӑҿӊӛӌӍ ӎӏӍӖӄӑҸӑӛ ӏҸӐӐӈҸӃ ӎӍ ӐӐӝӊӈҿࡏdouble x = 37;double* px = &x;void* p = px;int* py = p;шӊӒӘӗӎҾ ӚӊӐӓӖӓӚӊӊࡋ ࢂхҾӎӓӀҾ ӔӕӊӕӓӄҾ ʮȧǝƆࡓࢃ ࡶ ӖӔӕӓӖӊӐ ӘӜӊӗӅӐӡࡌ ࡎhttp://thecodelesscode.com/case/5?lang=ruߠࡏࡏеӄӌҸӋӄӖҿӐӈҸӨ ӎҸӋӨӑӛࡏࡏࡏхӏҿӄӋӒәҿӐӑҺҸ ҾӄӌҸӋӄӖҿӐӈӍӅ ӎҸӋӨӑӄбӌӒӑӏӄ ӔӒӌӈӗӄӄ ӌҿӊӛӃӨ ӐӍӃҾҸӑӛ ӋҸӐӐӄҺࡈ ӈӍӑӍӏӝӅ ҹӒҾҿӑӐӒәҿӐӑҺӍҺҸӑӛ ӎӍӐӊҿ ҺӝӕӍҾҸ ӄӃ ӌҿҿࡏцҸӃӋҿӏ ӋҸӐӐӄҺҸ ҾӍӊӂҿӌ ҹӝӑӛ ӄӃҺҿӐӑҿӌ ӌҸ ӋӍӋҿӌӑ ӈӍӋӎӄӊӨӗӄӄӎӏӍһӏҸӋӋӝࡏчҸӋӝӅ һӄҹӈӄӅ ӄ ӐҸӋӝӅ ӐӊӍӂӌӝӅ Һ ӏҸҹӍӑҿ ҺӄҾ ӎҸӋӨӑӄࡏжӐӑӛ ҿәҿ ҸҺӑӍӋҸӑӄӖҿӐӈҸӨ ӄ ӐӑҸӑӄӖҿӐӈҸӨ ӎҸӋӨӑӛࡈ ӌӍ ӄӕ ӍӎӄӐҸӌӄҿҺӝӕӍҾӄӑ ӃҸ ӏҸӋӈӄ ҾҸӌӌӍӅ ӊҿӈӗӄӄࡏ лӕ ӍӐӌӍҺӌӝҿ ӌҿҾӍӐӑҸӑӈӄࡇӔӄӈӐӄӏӍҺҸӌӌӝӅ ӏҸӃӋҿӏ ӄ ӌҿҾӍӐӑҸӑӍӖӌӍ һӄҹӈӍҿ ҺӏҿӋӨ ӂӄӃӌӄࡏࡄ бӝҾҿӊӨҿӑӐӨ ӄ ӍӐҺӍҹӍӂҾҸҿӑӐӨ ҾӄӌҸӋӄӖҿӐӈӄ ӎӍ ӃҸӎӏӍӐӒ ӎӏӍһӏҸӋӋӝࡏࡄ цҸӃӋҿӏ ӃҸҾҸҿӑӐӨ ҾӄӌҸӋӄӖҿӐӈӄࡏߢࡏࡏбӝҾҿӊҿӌӄҿ ҹӊӍӈҸ ӎҸӋӨӑӄȒŏȀȀȩż ࣌ ›ƚȒȩɟʿ °+ŏɾƚɯǞˌƚ࡙ɾ ࡷ ҹҿӃӃӌҸӈӍҺӝӅ ӗҿӊӍӖӄӐӊҿӌӌӝӅ ӑӄӎ ҾҸӌӌӝӕࡈ ӎӍҾӕӍҾӨәӄӅҾӊӨ ӕӏҸӌҿӌӄӨ ӊӧҹӍһӍ ӏҸӃӋҿӏҸ Һ ҹҸӅӑҸӕࡏеӏӒһӄҿ ӔӒӌӈӗӄӄ ҾӊӨ ҺӝҾҿӊҿӌӄӨ ӎҸӋӨӑӄ ࡫żŏȀȀȩżࡈ ɟƚŏȀȀȩż࡬ ҺӝӕӍҾӨӑӃҸ ӏҸӋӈӄ ҾҸӌӌӍһӍ ӈӒӏӐҸࡏvoid* malloc(size_t size);ыӒӌӈӗӄӨ ҺӝҾҿӊӨҿӑ ҹӊӍӈ ӎҸӋӨӑӄ ӏҸӃӋҿӏӍӋ size ҹҸӅӑ ӄ ҺӍӃҺӏҸәҸҿӑ ӒӈҸӃҸӑҿӊӛӌҸ ӌҸӖҸӊӍ ҹӊӍӈҸࡏ б ӐӊӒӖҸҿࡈ ҿӐӊӄ ӎҸӋӨӑӛ ҺӝҾҿӊӄӑӛ ӌҿ ӎӍӊӒӖӄӊӍӐӛࡈ ҺӍӃҺӏҸәҸҿӑNULLࡏ фҹӜӨҺӊҿӌҸ Һ ӃҸһӍӊӍҺӍӖӌӍӋ ӔҸӅӊҿ stdlib.hࡏߣࡏࡏфӐҺӍҹӍӂҾҿӌӄҿ ҹӊӍӈҸ ӎҸӋӨӑӄщӑҿӖӈӄ ӎҸӋӨӑӄ ӌҸ ӐҿӏҺҿӏӌӝӕ ӎӏӄӊӍӂҿӌӄӨӕࡈ ӈӍӑӍӏӝҿ ҾӍӊӂӌӝӏҸҹӍӑҸӑӛ ӌҿӐӈӍӊӛӈӍ ӊҿӑࡈ ӌҿҾӍӎӒӐӑӄӋӝࡏщӑҿӖӈӄ ӎҸӋӨӑӄ Һ ҾҿӐӈӑӍӎӌӝӕ ӎӏӄӊӍӂҿӌӄӨӕ ӌҿ ӑҸӈ ӈӏӄӑӄӖӌӝࡈ ӌӍӋӍһӒӑ ӄ ӎӏӄӖӄӌӨӑӛ ӌҿӒҾӍҹӐӑҺҸ ࡫ӐӋࡏ ӐӍҺӏҿӋҿӌӌӝҿ ҹӏҸӒӃҿӏӝ࡬ࡏvoid free(void* ptr);ыӒӌӈӗӄӨ ӍӐҺӍҹӍӂҾҸҿӑ ҹӊӍӈ ӎҸӋӨӑӄࡏ жӐӊӄ ptr ӏҸҺҿӌ NULLࡈ ӌӄӖҿһӍ ӌҿ ҾҿӊҸҿӑࡏфҹӜӨҺӊҿӌҸ Һ ӃҸһӍӊӍҺӍӖӌӍӋ ӔҸӅӊҿ stdlib.hࡏхӍӐӊҿ ҺӝӃӍҺҸ ӃӌҸӖҿӌӄҿ ӒӈҸӃҸӑҿӊӨ ptr ӍӐӑҸҿӑӐӨ ӎӏҿӂӌӄӋࡈ ӌӍӏҸӃӝӋҿӌӍҺӝҺҸӑӛ ҿһӍ ӌҿӊӛӃӨࡏуҿӄӐӎӍӊӛӃӒҿӋӒӧ ӎҸӋӨӑӛ ӌӒӂӌӍ ӍҹӨӃҸӑҿӊӛӌӍ ӍӐҺӍҹӍӂҾҸӑӛࡈ ӄӌҸӖҿ ӏҸӌӍ ӄӊӄӎӍӃҾӌӍ ӍӌҸ ӋӍӂҿӑ ӈӍӌӖӄӑӛӐӨ ࡫ӒӑҿӖӈҸ ӎҸӋӨӑӄ࡬ࡏߤࡏࡏхӏӄӋҿӏࡇ ӋҸӐӐӄҺ ҾӄӌҸӋӄӖҿӐӈӍһӍ ӏҸӃӋҿӏҸбӝҾҿӊҿӌӄҿ ӎҸӋӨӑӄ ӎӍҾ Ÿ ӗҿӊӝӕ ӖӄӐҿӊࡈ һҾҿ Ÿ ӃҸҾҸҿӑӐӨ ҺӍ ҺӏҿӋӨӄӐӎӍӊӌҿӌӄӨ ӎӏӍһӏҸӋӋӝࡏɯǞˌƚȩǀ ࡴ ӍӎҿӏҸӑӍӏࡈ ҺӝҾҸӧәӄӅ ӏҸӃӋҿӏ ӑӄӎӍҺ ҾҸӌӌӝӕࡏ уҸӎӏӄӋҿӏࡈӌҸ vȘɾƚȀ ʾߤߢ ɯǞˌƚȩǀ࡫ǞȘɾ࡬ ࣌࣌ ߠࡏࡏint n = read_number(); // 5int* p; // ???ߥࡏࡏхӏӄӋҿӏࡇ ӋҸӐӐӄҺ ҾӄӌҸӋӄӖҿӐӈӍһӍ ӏҸӃӋҿӏҸࡏࡐࡐࡐࡐࡐࡐࡐࡐࡐ0x100бӝҾҿӊҿӌӄҿ ӎҸӋӨӑӄ ӎӍҾ Ÿ ӗҿӊӝӕ ӖӄӐҿӊࡈ һҾҿ Ÿ ӃҸҾҸҿӑӐӨ ҺӍ ҺӏҿӋӨӄӐӎӍӊӌҿӌӄӨ ӎӏӍһӏҸӋӋӝࡏࡐࡐࡐɯǞˌƚȩǀ ࡴ ӍӎҿӏҸӑӍӏࡈ ҺӝҾҸӧәӄӅ ӏҸӃӋҿӏ ӑӄӎӍҺ ҾҸӌӌӝӕࡏ уҸӎӏӄӋҿӏࡈӌҸ vȘɾƚȀ ʾߤߢ ɯǞˌƚȩǀ࡫ǞȘɾ࡬ ࣌࣌ ߠࡏࡐࡐࡐ0x113int n = read_number(); // 5int* p; // 0x100p = malloc(n * sizeof(int));if (p == NULL) { /* error */ }ߥࡏࡏхӏӄӋҿӏࡇ ӋҸӐӐӄҺ ҾӄӌҸӋӄӖҿӐӈӍһӍ ӏҸӃӋҿӏҸࡏߟߣࡐࡐࡐ0x100ߟߣбӝҾҿӊҿӌӄҿ ӎҸӋӨӑӄ ӎӍҾ Ÿ ӗҿӊӝӕ ӖӄӐҿӊࡈ һҾҿ Ÿ ӃҸҾҸҿӑӐӨ ҺӍ ҺӏҿӋӨӄӐӎӍӊӌҿӌӄӨ ӎӏӍһӏҸӋӋӝࡏࡐࡐࡐɯǞˌƚȩǀ ࡴ ӍӎҿӏҸӑӍӏࡈ ҺӝҾҸӧәӄӅ ӏҸӃӋҿӏ ӑӄӎӍҺ ҾҸӌӌӝӕࡏ уҸӎӏӄӋҿӏࡈӌҸ vȘɾƚȀ ʾߤߢ ɯǞˌƚȩǀ࡫ǞȘɾ࡬ ࣌࣌ ߠࡏߟߣ0x113int n = read_number(); // 5int* p; // 0x100p = malloc(n * sizeof(int));if (p == NULL) { /* error */ }p[0] = p[n/2] = p[n-1] = 37;ߥࡏࡏхӏӄӋҿӏࡇ ӋҸӐӐӄҺ ҾӄӌҸӋӄӖҿӐӈӍһӍ ӏҸӃӋҿӏҸࡏࡐࡐࡐࡐࡐࡐࡐࡐࡐ0x100бӝҾҿӊҿӌӄҿ ӎҸӋӨӑӄ ӎӍҾ Ÿ ӗҿӊӝӕ ӖӄӐҿӊࡈ һҾҿ Ÿ ӃҸҾҸҿӑӐӨ ҺӍ ҺӏҿӋӨӄӐӎӍӊӌҿӌӄӨ ӎӏӍһӏҸӋӋӝࡏࡐࡐࡐɯǞˌƚȩǀ ࡴ ӍӎҿӏҸӑӍӏࡈ ҺӝҾҸӧәӄӅ ӏҸӃӋҿӏ ӑӄӎӍҺ ҾҸӌӌӝӕࡏ уҸӎӏӄӋҿӏࡈӌҸ vȘɾƚȀ ʾߤߢ ɯǞˌƚȩǀ࡫ǞȘɾ࡬ ࣌࣌ ߠࡏࡐࡐࡐ0x113int n = read_number(); // 5int* p; // 0x100p = malloc(n * sizeof(int));if (p == NULL) { /* error */ }p[0] = p[n/2] = p[n-1] = 37;free(p);ߥࡏࡏщӈҸӃҸӑҿӊӄ ӌҸ ӔӒӌӈӗӄӄࡏࡏࡏыӒӌӈӗӄӄ ӈҸӈ ҾҸӌӌӝҿɔȩʶ ࡴ ӔӒӌӈӗӄӨ ҺӍӃҺҿҾҿӌӄӨ Һ Ӑӑҿӎҿӌӛࡈ ӍҹӜӨҺӊҿӌҸ Һ ӔҸӅӊҿ ȒŏɾǕࡏǕࡏхӏӍӄӃӌӍӐӄӑӐӨ ӐӊҿҾӒӧәӄӋ ӍҹӏҸӃӍӋࡇ ӎҿӏҿӋҿӌӌҸӨ Ȓʿ࡙ǀʕȘż ࡴ ӢӑӍӒӈҸӃҸӑҿӊӛ ӌҸ ӔӒӌӈӗӄӧࡈ ӎӏӄӌӄӋҸӧәӒӧ ҾҺҸ ӎҸӏҸӋҿӑӏҸ ӑӄӎҸƇȩʕųȀƚ ӄ ҺӍӃҺӏҸәҸӧәӒӧ ӃӌҸӖҿӌӄҿ ӑӄӎҸ ƇȩʕųȀƚࡏб ӨӃӝӈҿ + Ӑ ӔӒӌӈӗӄӨӋӄ ӋӍӂӌӍ ӏҸҹӍӑҸӑӛ ӈҸӈ Ӑ ҾҸӌӌӝӋӄࡇdouble (*my_func)(double, double) = pow;double x = my_func(3, 2); // x = 9.0фӎҿӏҸӑӍӏ ҺӃӨӑӄӨ ҸҾӏҿӐҸ ॆ ҾӊӨ ӔӒӌӈӗӄӅ ӋӍӂӌӍ ӍӎӒӐӈҸӑӛ ࡫ӖҸәҿҺӐҿһӍ ӍӎӒӐӈҸҿӑӐӨ࡬ࡏыӒӌӈӗӄӨ ࡴ ӢӑӍ ӌҸҹӍӏ ҹҸӅӑӍҺ Һ ӎҸӋӨӑӄࡈ ӈӍҾӄӏӒӧәӄӕ ӑҿӊӍ ӢӑӍӅ ӔӒӌӈӗӄӄ ӐӎӍӋӍәӛӧ ӋҸӘӄӌӌӝӕ ӈӍӋҸӌҾࡏ кӌҸӖӄӑࡈ ӋӍӂӌӍ ҺӃӨӑӛ ҸҾӏҿӐ ӢӑӍһӍ ࢀӌҸҹӍӏҸҹҸӅӑӍҺࢁࡏфӎҿӏҸӑӍӏ ӏҸӃӝӋҿӌӍҺӝҺҸӌӄӨ ࡁ ӎӏӄ ҺӝӃӍҺҿ ӔӒӌӈӗӄӄ ӋӍӂӌӍӍӎӒӐӈҸӑӛ ࡫ӖҸәҿ ҺӐҿһӍ ӍӎӒӐӈҸҿӑӐӨ࡬ࡏкҸӋҿӑӄӋࡈ ӖӑӍ Һӝ Ӓӂҿ ҺӐӑӏҿӖҸӊӄӐӛ Ӑ ӑӄӎҸӋӄࡈ ӍӈӏӒӂҸӧәӄӋӄ ӄӋӨӎҿӏҿӋҿӌӌӍӅࡇ ǞȘɾ ŏɟɟ࡟ߝߜࡠ࡟ߡࡠ ࡴ Һ ҾҸӌӌӍӋ ӐӊӒӖҸҿ ӎҿӏҿӋҿӌӌҸӨ ӄӋҿҿӑӄӋӨ ŏɟɟ ӄ ӑӄӎ ǞȘɾ࡟ߝߜࡠ࡟ߡࡠࡏаӍӊҿҿ ӔӍӏӋҸӊӛӌӍࡇdouble (*my_func)(double, double) = &pow;double x = (*my_func)(3, 2); // x = 9.0ߝߝࡏࡏхӏӄӋҿӏ ӖӄӐӊҿӌӌӍһӍ ҺӝӖӄӐӊҿӌӄӨ ӎӏӍӄӃҺӍҾӌӍӅ Һ ӑӍӖӈҿб ҾҸӌӌӍӋ ӎӏӄӋҿӏҿ Ӑ ӎӍӋӍәӛӧ ӒӈҸӃҸӑҿӊҿӅ ӌҸ ӔӒӌӈӗӄӄ Ӌӝ ӋӍӂҿӋӖӄӐӊҿӌӌӍ ҺӝӖӄӐӊӨӑӛ ӎӏӍӄӃҺӍҾӌӝҿ ӋҸӑҿӋҸӑӄӖҿӐӈӄӕ ӔӒӌӈӗӄӅࡈӈӍӑӍӏӝҿ ӎӏӄӌӄӋҸӧӑ ӍҾӄӌ ӎҸӏҸӋҿӑӏ ӑӄӎҸ ƇȩʕųȀƚ ӄ ҺӍӃҺӏҸәҸӧӑӏҿӃӒӊӛӑҸӑ ӑӄӎҸ ƇȩʕųȀƚࡏdouble diff(double x, double (*f)(double)) {double dx = 0.01;return (f(x + dx) - f(x)) / dx;}кҸӋҿӑӄӋࡈ ӖӑӍ Ӌӝ ӋӍӂҿӋ ӎҿӏҿҾҸҺҸӑӛ ӎҸӏҸӋҿӑӏӍӋ ӌҿ ӑӍӊӛӈӍҹӄҹӊӄӍӑҿӖӌӝҿ ӔӒӌӈӗӄӄ ࡫ӌҸӎӏӄӋҿӏࡈ ɯǞȘ ӄ żȩɯ ӄӃ ȒŏɾǕࡏǕ࡬ࡈ ӌӍ ӄӐӍҹӐӑҺҿӌӌӝҿ ӔӒӌӈӗӄӄ ࡫ӌҸӎӏӄӋҿӏࡈ ɯɛʕŏɟƚ࡬ࡏdouble square(double x) {return x * x;}›࡙Úv ࡴ ӈӍӌӐӑҸӌӑҸ ӄӃ ȒŏɾǕࡏǕprintf("%g\n", diff(M_PI/3, sin)); // 0.495662printf("%g\n", diff(M_PI/6, cos)); // -0.504322printf("%g\n", diff(3, square));// 6.01ߝߞࡏࡏчӄӋҺӍӊӝ ӄ ӈӍҾӄӏӍҺӈӄࡏࡏࡏчӄӋҺӍӊӝ Һ +чӄӋҺӍӊӝ ӃҸҾҸӧӑӐӨ Һ ӍҾӄӌҸӏӌӝӕ ӈҸҺӝӖӈҸӕࡈ ӕӏҸӌӨӑӐӨ Һ ӎҿӏҿӋҿӌӌӝӕ ӑӄӎҸ charࡏchar x = 'H';char y = 'i';printf("%c%c\n", x, y); // HiߝߠࡏࡏпӍҾӄӏӍҺӈӄшӍ ҿӐӑӛ ӐӄӋҺӍӊӝ ӎӏҿҾӐӑҸҺӊӨӧӑӐӨ ӎӏӍӐӑӍ ӐҺӍӄӋ ӗҿӊӍӖӄӐӊҿӌӌӝӋӈӍҾӍӋࡏȒƚɟǞżŏȘ ɯɾŏȘƇŏɟƇ żȩƇƚ ǀȩɟ ǞȘǀȩɟȒŏɾǞȩȘ ǞȘɾƚɟżǕŏȘǃƚࡏпӍҾӄӏӍҺӈҸ ࡴ ӐӍӍӑҺҿӑӐӑҺӄҿ ӋҿӂҾӒ ӐӄӋҺӍӊӍӋ ӄ ӗҿӊӍӖӄӐӊҿӌӌӝӋ ӈӍҾӍӋࡏшҸҹӒӊӨӗӄӨ ࡴ һӍӏӄӃӍӌӑҸӊӛӌӝӅ ӎӏӍҹҿӊ ҾӊӨ ӔӍӏӋҸӑӄӏӍҺҸӌӄӨӑҸҹӊӄӗࡏë+vv ࡴ ӔӒӌҾҸӋҿӌӑҸӊӛӌҸӨ ߣࡷҹӄӑӌҸӨ ӈӍҾӄӏӍҺӈҸࡇࡄ ߟߞ ӒӎӏҸҺӊӨӧәӄӕ ӐӄӋҺӍӊҸࡈࡄ '\0'ࡈ ӈӍҾ ߜ ࡴ ӎӒӐӑӍӅ ӐӄӋҺӍӊࡈࡄ '\t'ࡈ ӈӍҾ ߥ ࡴ ӑҸҹӒӊӨӗӄӨࡈࡄ '\n'ࡈ ӈӍҾ ߝߜ ࡴ ӎҿӏҿҺӍҾ ӐӑӏӍӈӄࡈࡄ ࡊࡄ ߥߢ ӄӌӔӍӏӋҸӗӄӍӌӌӝӕ ӐӄӋҺӍӊӍҺࡏࡄ '0'..'9' ࡴ ӗӄӔӏӝࡈࡄ 'a'..'z'ࡈ 'A'..'Z' ࡴ ҹӒӈҺӝࡈࡄ ',', '?', ...

ࡴ ӎӒӌӈӑӒҸӗӄӨࡏࡄ ࡊߝߡࡏࡏчӄӋҺӍӊӝ ӈҸӈ ӖӄӐӊҸчӄӋҺӍӊ ࡴ ӍҾӌӍҺӏҿӋҿӌӌӍ ӄ ӐӄӋҺӍӊࡈ ӄ ӈӍҾࡏ бӐҿ ӃҸҺӄӐӄӑ ӊӄӘӛ ӍӑӐӎӍӐӍҹҸ ҿһӍ ӑӏҸӈӑӍҺҸӌӄӨࡏchar a = 'X';printf("%c\n", a); // Xprintf("%d\n", a); // 88char b = a + 1;printf("%c\n", b); // YߝߢࡏࡏуҸӗӄӍӌҸӊӛӌӝҿ ӐӄӋҺӍӊӝпфлࡷߤ ӄ ĦǞȘƇȩʶɯࡷߝߞߡߝ ӌҿ ӐӍҺӋҿӐӑӄӋӝ ҾӏӒһ Ӑ ҾӏӒһӍӋ ӄ ӌҿӐӍҺӋҿӐӑӄӋӝ ӐӍ ҺӐҿӋӄ ӍӐӑҸӊӛӌӝӋӄ ӌҸӗӄӍӌҸӊӛӌӝӋӄӈӍҾӄӏӍҺӈҸӋӄ ࡴ ҹҸӏҾҸӈࡋб ҹӏҸӒӃҿӏҸӕ ҾӍ Ӑӄӕ ӎӍӏ ҿӐӑӛ ҺӍӃӋӍӂӌӍӐӑӛ ҺӏӒӖӌӒӧ ҺӝҹӏҸӑӛӈӍҾӄӏӍҺӈӒ ӐӑӏҸӌӄӗӝࡏ л ӢӑӍ ӄӌӍһҾҸ ҹӝҺҸҿӑ ӎӍӊҿӃӌӍࡏЯ ӖӑӍ ҾҿӊҸӑӛࡈ ҿӐӊӄ ӕӍӖҿӑӐӨ ӄӐӎӍӊӛӃӍҺҸӑӛ ӈӄӏӄӊӊӄӗӒࡈ ӒӋӊӨӒӑӝ ӄ ӄҿӏӍһӊӄӔӝࡐߤࡷҹӄӑӌӝҿ ӈӄӏӄӊӊӄӖҿӐӈӄҿ ӈӍҾӄӏӍҺӈӄࡈ ҹҸӃӄӏӒӧәӄҿӐӨ ӌҸ ë+vvࡇ пфлࡷߤࡈĦǞȘƇȩʶɯࡷߝߞߡߝࡈ ࡊуҸ ӎӏҸӈӑӄӈҿ ӈҸӈࡷӑӍ ӑҸӈࡇ ӄӘॏӧӜӏӚ ॊӝӕӜөॏӘӡӘӜӏӣӘӚߝߣࡏࡏўӌӄӈӍҾўӌӄӈӍҾ ӌҸ ҾҸӌӌӝӅ ӋӍӋҿӌӑ ӄӐӎӍӊӛӃӒҿӑӐӨ ӎӍ ӒӋӍӊӖҸӌӄӧ ҺӍӋӌӍһӄӕ ӨӃӝӈҸӕ ӎӏӍһӏҸӋӋӄӏӍҺҸӌӄӨࡈ Һ ӍӎҿӏҸӗӄӍӌӌӝӕ ӐӄӐӑҿӋҸӕࡈ ӌҸҹӍӊӛӘӄӌӐӑҺҿ ӄӌӑҿӏӌҿӑ ӐҸӅӑӍҺࡏшӍӌӈӍӐӑӄ ӈӍҾӄӏӍҺҸӌӄӨ ӧӌӄӈӍҾӌӝӕ ӐӄӋҺӍӊӍҺ Һ ҺӄҾҿ ҹҸӅӑӍҺ ҺҾҸӌӌӍӅ ӊҿӈӗӄӄ ӌҿ ӏҸӐӐӋҸӑӏӄҺҸҿӑӐӨࡏ шҸӈӂҿ ӌҿ ӏҸӐӐӋҸӑӏӄҺҸӧӑӐӨӐӎӍӐӍҹӝ ӄӐӎӍӊӛӃӍҺҸӌӄӨ ӧӌӄӈӍҾҸ Һ ӎӏӍһӏҸӋӋҸӕ ӌҸ +ࡏўӌӄӈӍҾ ࡴ ӋӌӍһӍҹҸӅӑӍҺҸӨ ӈӍҾӄӏӍҺӈҸࡈ ӎӍӈӏӝҺҸӧәҸӨ ӎӍӖӑӄ ҺӐҿ ӎӄӐӛӋҿӌӌӝҿӨӃӝӈӄࡏхӍӃҺӍӊӨҿӑ ӈӍҾӄӏӍҺҸӑӛ ߝ ߝߝߞ ߜߢߠ ӐӄӋҺӍӊӍҺࡏ б ҺҿӏӐӄӄ ߥࡏߜࡈ ӄӧӌӛ ߞߜߝߢ һࡏࡈӄӐӎӍӊӛӃӒҿӑӐӨ ӊӄӘӛ ߝߞߤ ߞߟߣࡏлӌӑҿӏҿӐӌҸӨ ӍҹӃӍӏӌҸӨ ӊҿӈӗӄӨ ӎӏӍ ӍӐӍҹҿӌӌӍӐӑӄ ӧӌӄӈӍҾҸ Ӑ÷ƚżǕ÷ŏȀǺɯॅŸëĆࡇ ǕɾɾɔɯࡇࡕࡕɾƚżǕɾŏȀǺɯࡏȘɯʕࡏɟʕࡕߟߢчӍҾҿӏӂӄӑ ҺӐҿ ӌҸӗӄӍӌҸӊӛӌӝҿ ӐӄӋҺӍӊӝࡈ ӋҸӑҿӋҸӑӄӖҿӐӈӄҿ ӐӄӋҺӍӊӝࡈ ӐӄӋҺӍӊӝҾӏҿҺӌӄӕ ӎӄӐӛӋҿӌӌӍӐӑҿӅ ӄ ӋӌӍһӍҿ ҾӏӒһӍҿࡈ ҺӈӊӧӖҸӨ ☺ ☹ ӄ ҾҸӂҿ ࡋߝߤࡏࡏчӑӏӍӈӄࡏࡏࡏчӑӏӍӈӄкҸӋҿӑӄӋࡈ ӖӑӍ ҾӊӨ ӐӑӏӍӈӄ Ҿӊӄӌӝ Ÿ ӌҿӍҹӕӍҾӄӋ ӋҸӐӐӄҺ Ҿӊӄӌӝ ӈҸӈӋӄӌӄӋӒӋ ŸࣹߝࡏчӑӏӍӈҸ ࡴ ӢӑӍ ӌҸҹӍӏ ӐӄӋҺӍӊӍҺࡏ б ӨӃӝӈҿ + ӐӑӏӍӈӄ ӎӏҿҾӐӑҸҺӊӨӧӑӐӨ Һ ҺӄҾҿӋҸӐӐӄҺӍҺ ӐӄӋҺӍӊӍҺ ӑӄӎҸ charࡏ пӍӌӐӑҸӌӑӌӝҿ ӐӑӏӍӈӄ ӃҸҾҸӧӑӐӨ Һ ҾҺӍӅӌӝӕӈҸҺӝӖӈҸӕࡏцҸӃӋҿӏ ӋҸӐӐӄҺҸࡈ Һ ӈӍӑӍӏӍӋ ӕӏҸӌӄӑӐӨ ӐӑӏӍӈҸ ࢆmǞࢆ ࡴ ߟ ҹҸӅӑҸࡏеӊӄӌҸ ӐӑӏӍӈӄ ӨҺӌӍ ӌҿ ӕӏҸӌӄӑӐӨࡇ ӎӍӐӊҿ ӎӍӐӊҿҾӌҿһӍ ӐӄӋҺӍӊҸ ӐӑӏӍӈӄ ӕӏҸӌӄӑӐӨӐӎҿӗӄҸӊӛӌӝӅ ӐӄӋҺӍӊ '\0'ࡏchar* str = "Hi";printf("%s\n", str);// Hiprintf("%d - %c\n", str[0], str[0]); // 72 - Hprintf("%d - %c\n", str[1], str[1]); // 105 - iprintf("%d - %c\n", str[2], str[2]); // 0 -ߞߜࡏࡏшӍӌӈӍӐӑӛ Ӑ ӄӌӄӗӄҸӊӄӃҸӗӄҿӅ ӐӑӏӍӈб ӎҿӏҺӍӋ ӐӊӒӖҸҿ ӎҿӏҿӋҿӌӌҸӨ ɾƚɯɾ ӒӈҸӃӝҺҸҿӑӐӨ ӌҸ ӐӎҿӗӄҸӊӛӌӒӧӍҹӊҸӐӑӛ ӎҸӋӨӑӄࡈ ҾӍӐӑӒӎӌӒӧ ӑӍӊӛӈӍ ҾӊӨ ӖӑҿӌӄӨࡈ һҾҿ ӕӏҸӌӨӑӐӨ ҺӐҿӈӍӌӐӑҸӌӑӌӝҿ ӐӑӏӍӈӄࡏбӍ ҺӑӍӏӍӋ ӐӊӒӖҸҿ ɾƚɯɾ ӒӈҸӃӝҺҸҿӑ ӌҸ ӋҸӐӐӄҺ Һ ӊӍӈҸӊӛӌӍӅ ӎҸӋӨӑӄࡈҾӍӐӑӒӎӌӍӅ ҾӊӨ ӖӑҿӌӄӨ ӄ ӃҸӎӄӐӄࡈ Һ ӈӍӑӍӏӝӅ ҹӝӊӍ ӐӈӍӎӄӏӍҺҸӌӍӐӍҾҿӏӂӄӋӍҿ ӈӍӌӐӑҸӌӑӌӍӅ ӐӑӏӍӈӄࡏࡄ test ࡴ ӒӈҸӃҸӑҿӊӛ ӌҸ ӈӍӌӐӑҸӌӑӌӒӧ ӐӑӏӍӈӒࡏchar* test = "cat";test[2] = 'r'; // run time errorࡄ test ࡴ ӋҸӐӐӄҺࡈ ӎӏӍӄӌӄӗӄҸӊӄӃӄӏӍҺҸӌӌӝӅ ӈӍӌӐӑҸӌӑӌӍӅ ӐӑӏӍӈӍӅࡏchar test[] = "cat";test[2] = 'r';printf("%s\n", test); // carߞߝࡏࡏпӍӌҿӗ ӑӏҿӑӛҿӅ ӊҿӈӗӄӄߞߞࡏ.