第一题：gets［str］能用于输入整形过实形变量吗？puts呢？ 下面C语言函数的作用：puts(str),gets(str)...
c\u8bed\u8a00 gets\u51fd\u6570 puts\u51fd\u6570\u3000\u3000\u6570\u7ec4\u7684\u957f\u5ea6\u5f53\u7136\u6709\u7528\u4e86\u3002\u4f60\u7ed9\u6570\u7ec4\u6307\u5b9a\u591a\u5927\uff0c\u8fd9\u91cc\u5c31\u7684\u5b57\u7b26\u4e32\u957f\u5ea6\u5bb9\u7eb3\u91cf\u5c31\u662f\u591a\u5927\u3002
\u3000\u3000\u8d8a\u754c\u8bbf\u95ee\u662f\u8bed\u8a00\u7684\u672a\u5b9a\u4e49\u884c\u4e3a\uff0c\u4e0d\u80fd\u4f9d\u8d56\u4e8e\u8fd9\u79cd\u884c\u4e3a\u3002\uff08\u5373\u4f7f\u770b\u8d77\u6765\u6709\u65f6\u5019\u5b83\u4e0d\u51fa\u9519\uff09
\u3000\u3000\u4f60\u8fd9\u91cc\u7a0b\u5e8f\u6ca1\u6709\u51fa\u73b0\u95ee\u9898\uff0c\u4ec5\u4ec5\u662f\u5de7\u5408\u800c\u5df2\u3002\u5177\u4f53\u4ec0\u4e48\u65f6\u5019\u6ea2\u51fa\u4f1a\u5f71\u54cd\u7a0b\u5e8f\u6267\u884c\uff0c\u53d6\u51b3\u4e8e\u5e73\u53f0\u548c\u7f16\u8bd1\u5668\u5b9e\u73b0\u3002
\u3000\u3000\u6253\u4e2a\u6bd4\u65b9\uff0c\u5982\u679c\u6709\u4e2a\u53d8\u91cf\u7d27\u8ddf\u5728\u6570\u7ec4\u540e\u9762\uff0c\u6570\u7ec4\u8d8a\u754c\u4e86\uff0c\u90a3\u4e48\u8fd9\u4e2a\u53d8\u91cf\u5c31\u4f1a\u88ab\u6539\u53d8\u3002
\u3000\u3000\u6211\u7ed9\u4e00\u4e2a\u4f8b\u5b50\uff1a
#include int main(int argc, char *argv[]){ char str[3]; char c = 'x'; printf("Key in str: "); gets(str); printf("str = %s, c = %c\n", str, c); return 0;}
\u3000\u3000\u6211\u4f7f\u7528 64 \u4f4d Linux \u7f16\u8bd1\u8fd0\u884c\u7684\u7ed3\u679c\u5982\u56fe\u3002\u82e5\u770b\u4e0d\u6e05\u695a\u8bf7\u53f3\u952e\u70b9\u5f00\u539f\u56fe\u3002
\u3000\u3000\u5de6\u4e0b\u89d2\u7a97\u53e3\u663e\u793a\u4e86\u6267\u884c\u60c5\u51b5\uff1a
\u3000\u3000\u7b2c\u4e00\u6b21\uff0c\u6211\u8f93\u5165\u4e8616\u4e2a\u5b57\u7b26\uff0c\u7ed3\u679c\u548c str \u65e0\u5173\u7684 c \u53d8\u6210\u4e86 \u6211\u8f93\u5165\u672b\u5c3e\u7684 'F'\uff0c\u8fd9\u6b63\u662f\u6211\u8f93\u5165\u7684\u7b2c 16 \u4e2a\u5b57\u7b26\uff08\u4ece\u96f6\u7b97\u662f15\uff09
\u3000\u3000\u7b2c\u4e8c\u6b21\uff0c\u6211\u8f93\u5165\u4e8615\u4e2a\u5b57\u7b26\uff0c\u7ed3\u679c c \u53d8\u6210\u4e86 '\0'\uff0c\u800cC\u8bed\u8a00\u6570\u7ec4\u672b\u5c3e\u7684 '\0' \u4e5f\u662f\u6b63\u662f str \u7684\u7b2c 16 \u4f4d\uff0c\u5373 str[15] \uff08\u4e0b\u6807\u4ece\u96f6\u5f00\u59cb\uff09
\u3000\u3000\u7b2c\u4e09\u6b21\uff0c\u6211\u8f93\u4e86 14 \u4e2a\u5b57\u7b26\uff0c\u52a0\u4e0a\u672b\u5c3e\u7684 \0 \u662f 15 \u4e2a\u3002\u6b64\u65f6 c \u6ca1\u6709\u88ab\u6539\u53d8\uff0c\u4ecd\u7136\u662f \u2018x'.
\u3000\u3000\u53ef\u4ee5\u731c\u60f3\u3002str \u548c c \u5728\u5185\u5b58\u4e0a\u76f8\u5dee 15 \u4e2a\u5b57\u8282\uff08\u56e0\u4e3a sizeof(char) \u6b63\u597d 1 \u5b57\u8282\uff09\u3002
\u3000\u3000\u628a\u7a0b\u5e8f\u7528 objdump \u53cd\u6c47\u7f16\uff08\u53f3\u4e0a\u7a97\u53e3\uff09\u3002\u53ef\u4ee5\u770b\u51fa\uff1a
\u3000\u3000movb $0x78, -0x1(%rbp) \u8fd9\u4e00\u53e5\u5bf9\u5e94\u7684\u5c31\u662f C \u8bed\u8a00\u7684 char c = 'x', \u5b57\u7b26x \u7684 ascii \u7801\u662f\u5341\u516d\u8fdb\u5236 78. \u6240\u4ee5\u53ef\u4ee5\u770b\u51fa\uff0cc \u7684\u5730\u5740\u662f %rbp \u5bc4\u5b58\u5668\u50a8\u5b58\u91cf\u5de6\u79fb 0x1 \u5b57\u8282\uff0c\u4f60\u53ef\u4ee5\u7406\u89e3\u6210\u5750\u6807\u4e3a -1\uff1b
\u3000\u3000\u4ece gets(str) \u8c03\u7528\u4e0b\u9762\u7684\u6c47\u7f16\u4ee3\u7801\u53ef\u4ee5\u627e\u5230\uff0c \u800c str \u7684\u5730\u5740\u4e3a %rbp \u5bc4\u5b58\u5668\u50a8\u5b58\u91cf\u5de6\u79fb 0x10 \u5b57\u8282\uff0c\u4e5f\u5c31\u662f\u5341\u8fdb\u5236\u7684 -16\u3002
\u3000\u3000\u8fd9\u4e8c\u8005\u6b63\u597d\u76f8\u5dee 15\uff0c \u9a8c\u8bc1\u4e86\u6211\u4eec\u7684\u731c\u60f3\u3002
\u3000\u3000\u7eaf\u624b\u5de5\u7801\u5b57\u622a\u56fe\uff0c\u671b\u91c7\u7eb3\u3002
puts(str)\uff1a\u8f93\u51fa\u5b57\u7b26\u4e32str\u7684\u5185\u5bb9\u3002
gets(str)\uff1a\u8f93\u5165\u5b57\u7b26\u4e32\uff0c\u5b58\u5165str\u8868\u793a\u7684\u7a7a\u95f4\u3002
strcmp(str1,str2)\uff1a\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\uff0cstr1>str2\u8fd4\u56de\u503c>0,str1==str2\u8fd4\u56de\u503c\u4e3a0\uff0cstr1<str2\u8fd4\u56de\u503c<0
strcpy(str1,str2)\uff1a\u5c06\u5b57\u7b26\u4e32str2\u590d\u5236\u5230str1\u3002
int main()
{
char str[10] = {NULL};
int n;
float m;
gets(str);//gets是字符串输入,并不能输入整形和浮点
//但可通过sscanf函数来格式化成相对应的值到变量
sscanf(str,"%d",&n);//将字符串里按整形格式化到变量
printf("%d\n",n);
sscanf(str,"%f",&m);//将字符串按浮点格式化到变量
printf("%f\n",m);
puts(str);
return 0;//你输入一个整数或有小数点的数值测试一下就知道了,如12.12
}
//给你写个例子供参考吧...
绛旓細gets(str);//gets鏄瓧绗︿覆杈撳叆,骞朵笉鑳借緭鍏ユ暣褰㈠拰娴偣 //浣嗗彲閫氳繃sscanf鍑芥暟鏉ユ牸寮忓寲鎴愮浉瀵瑰簲鐨勫煎埌鍙橀噺 sscanf(str,"%d",&n);//灏嗗瓧绗︿覆閲屾寜鏁村舰鏍煎紡鍖栧埌鍙橀噺 printf("%d\n",n);sscanf(str,"%f",&m);//灏嗗瓧绗︿覆鎸夋诞鐐规牸寮忓寲鍒板彉閲 printf("%f\n",m);puts(str);return 0;//浣犺緭鍏ヤ竴...
绛旓細gets鍑芥暟鐨勫師鍨嬩负char *gets锛屽叾涓str鏄竴涓瓧绗︽暟缁勶紝鐢ㄤ簬瀛樺偍杈撳叆鐨勫瓧绗︿覆銆2. 浣跨敤鏂瑰紡锛氳皟鐢╣ets鍑芥暟鏃讹紝闇瑕佹彁渚涗竴涓瓧绗︽暟缁勭殑鎸囬拡浣滀负鍙傛暟銆傚嚱鏁颁細浠庢爣鍑嗚緭鍏ヨ鍙栧瓧绗︼紝骞跺瓨鍌ㄥ湪鎻愪緵鐨勬暟缁勪腑锛岀洿鍒伴亣鍒版崲琛岀鎴朎OF銆傛敞鎰忥紝璇诲彇鐨勫瓧绗︿覆浼氬寘鍚崲琛岀鏈韩銆傛澶栵紝鍑芥暟浼氳繑鍥炴寚鍚戣緭鍏ュ瓧绗︿覆鐨勬寚閽堛傚鏋...
绛旓細1銆gets() 鍑芥暟鏄粠閿洏杈撳叆瀛楃涓诧紝璇ュ嚱鏁板彧鏈変竴涓弬鏁般傚弬鏁扮被鍨嬩负 char* 鍨嬶紝鍗 str 鍙互鏄竴涓瓧绗︽寚閽堝彉閲忓悕锛屼篃鍙互鏄竴涓瓧绗︽暟缁勫悕銆傛墦寮缂栬緫鍣紝鏂板缓涓涓猚璇█鏂囦欢锛屽紩鍏ユ爣鍑嗗簱骞舵柊寤轰富鍑芥暟锛2銆乬ets() 鍑芥暟鐨勫姛鑳芥槸浠庤緭鍏ョ紦鍐插尯涓鍙栦竴涓瓧绗︿覆瀛樺偍鍒板瓧绗︽寚閽堝彉閲 str 鎵鎸囧悜鐨勫唴瀛樼┖闂...
绛旓細涓銆侀棶棰樻弿杩帮細浠庨敭鐩樿緭鍏ヤ竴涓瓧绗︿覆缁str鍜屼竴涓瓧绗︾粰c锛屽垹闄tr涓殑鎵鏈夊瓧绗骞惰緭鍑哄垹闄ゅ悗鐨勫瓧绗︿覆str銆1銆佽緭鍏锛氱涓琛屾槸涓涓瓧绗︿覆锛 绗簩琛屾槸涓涓瓧绗︺2銆佽緭鍑猴細鍒犻櫎鎸囧畾瀛楃鍚庣殑瀛楃涓层備簩銆佽璁℃濊矾锛1銆 鍚屾彃鍏ラ棶棰橈紝瀹氫箟涓や釜瀛楃鏁扮粍a锛宐銆備互鍙婃爣蹇楀垹闄や綅缃殑int鍨媝os銆2銆佺敤gets鍑芥暟...
绛旓細"); scanf("%c",&ch); fflush(stdin);//鍔犱笂杩欏彞锛屾竻鎺夎緭鍏ュ瓧绗﹀悗锛屼綘鍐嶈緭鍏ョ殑鍥炶溅绗 printf("Input a string: "); char str[80]; gets(str); printf("%c\n",ch); puts(str); return 0;} 杩欐牱灏辨纭簡锛氳繖涓棶棰樻槸姣旇緝鍏稿瀷鐨勶紝涓昏灏辨槸鐢变簬scanf鍑芥暟鐨勪笉瀹夊叏鎬ч犳垚鐨勩
绛旓細gets(str);printf("%c\n",ch);puts(str);return 0;} 瀛楃涓 鍥犱负鏈嚱鏁板彲浠ユ棤闄愯鍙栵紝鏄撳彂鐢熸孩鍑恒傚鏋滄孩鍑猴紝澶氬嚭鏉ョ殑瀛楃灏嗚鍐欏叆鍒板爢鏍堜腑锛岃繖灏辫鐩栦簡鍫嗘爤鍘熷厛鐨勫唴瀹癸紝鐮村潖涓涓垨澶氫釜涓嶇浉鍏冲彉閲忕殑鍊笺傝繖涓簨瀹炲鑷磄ets鍑芥暟鍙傜敤浜庣帺鍏风▼搴忥紝涓轰簡閬垮厤杩欑鎯呭喌锛鍙互鐢fgets(stdin) (fgets瀹為檯涓...
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绛旓細puts(str)锛氳緭鍑哄瓧绗︿覆str鐨勫唴瀹广gets(str)锛氳緭鍏ュ瓧绗︿覆锛屽瓨鍏tr琛ㄧず鐨勭┖闂淬俿trcmp(str1,str2)锛氭瘮杈冧袱涓瓧绗︿覆锛宻tr1>str2杩斿洖鍊>0,str1==str2杩斿洖鍊间负0锛宻tr1<str2杩斿洖鍊<0 strcpy(str1,str2)锛氬皢瀛楃涓瞫tr2澶嶅埗鍒皊tr1銆
绛旓細c璇█锛実ets()鍑芥暟鐢ㄦ潵浠庢爣鍑嗚緭鍏ヨ澶囷紙閿洏锛夎鍙栧瓧绗︿覆鐩村埌鎹㈣绗︾粨鏉燂紝浣嗘崲琛岀浼氳涓㈠純锛岀劧鍚庡湪鏈熬娣诲姞'\0'瀛楃銆傚叾璋冪敤鏍煎紡涓锛歡ets(s)銆傚叾涓璼涓哄瓧绗︿覆鍙橀噺锛堝瓧绗︿覆鏁扮粍鍚嶆垨瀛楃涓叉寚閽堬級銆傚鏋滀负鍗曚釜瀛楃鎸囬拡锛岀紪璇戣繛鎺ヤ笉浼氭湁閿欒锛屼絾杩愯鍚庡唴瀛樻孩鍑洪敊璇
绛旓細涓嶅銆gets() 鍑芥暟鍙互璇诲彇涓鏁磋瀛楃涓诧紝鑰屼笉鏄竴涓瓧绗︺俫ets() 鍑芥暟鐨勪綔鐢ㄦ槸浠庢爣鍑嗚緭鍏ユ祦 stdin 涓鍙栦竴琛屽瓧绗︼紝骞跺皢鍏跺偍瀛樺湪鎸囧畾鐨勫瓧绗︿覆鏁扮粍涓備緥濡備笅闈㈢殑浠ｇ爜锛歚``char str[100];gets(str);```杩欎細灏嗚緭鍏ョ殑涓鏁磋瀛楃璇诲彇鍒 str 鏁扮粍涓傚洜姝わ紝gets() 鍑芥暟鍙互璇诲彇澶氫釜瀛楃锛岃屼笉鏄...
