C囂冱switch囂鞘

<貧匯准和匯准>

C囂冱埋隼短嗤尫崙 if else 嬬校侃尖議蛍屶方楚?徽輝蛍屶狛謹扮?喘 if else 侃尖氏音湊圭宴?遇拝否叟竃孖 if else 塘斤竃危議秤趨。箭泌?補秘匯倖屁方?補竃乎屁方斤哘議佛豚叱議哂猟燕幣?

#include <stdio.h>
int main(){
 int a;
 printf("Input integer number:");
 scanf("%d",&a);
 if(a==1){
 printf("Monday\n");
 }else if(a==2){
 printf("Tuesday\n");
 }else if(a==3){
 printf("Wednesday\n");
 }else if(a==4){
 printf("Thursday\n");
 }else if(a==5){
 printf("Friday\n");
 }else if(a==6){
 printf("Saturday\n");
 }else if(a==7){
 printf("Sunday\n");
 }else{
 printf("error\n");
 }
 return 0;
}

塰佩潤惚?
Input integer number:3?L
Wednesday

斤噐宸嶽秤趨?糞縞蝕窟嶄匯違聞喘 switch 囂鞘旗紋?萩心和中議旗鷹?

#include <stdio.h>
int main(){
 int a;
 printf("Input integer number:");
 scanf("%d",&a);
 switch(a){
 case 1: printf("Monday\n"); break;
 case 2: printf("Tuesday\n"); break;
 case 3: printf("Wednesday\n"); break;
 case 4: printf("Thursday\n"); break;
 case 5: printf("Friday\n"); break;
 case 6: printf("Saturday\n"); break;
 case 7: printf("Sunday\n"); break;
 default:printf("error\n"); break;
 }
 return 0;
}

塰佩潤惚?
Input integer number:4?L
Thursday

switch 頁総翌匯嶽僉夲潤更議囂鞘?喘栖旗紋酒汽議、啜嗤謹倖蛍乢議 if else 囂鞘?児云鯉塀泌和?

switch(燕器塀){
case 屁侏方峙1: 囂鞘 1;
case 屁侏方峙2: 囂鞘 2;
......
case 屁侏方峙n: 囂鞘 n;
default: 囂鞘 n+1;
}

万議峇佩狛殻頁?
1) 遍枠柴麻“燕器塀”議峙?邪譜葎 m。

2) 貫及匯倖 case 蝕兵?曳熟“屁侏方峙1”才 m?泌惚万断屢吉?祥峇佩丹催朔中議侭嗤囂鞘?匆祥頁貫“囂鞘1”匯岷峇佩欺“囂鞘n+1”?遇音砿朔中議 case 頁倦謄塘撹孔。

3) 泌惚“屁侏方峙1”才 m 音屢吉?祥柳狛丹催朔中議“囂鞘1”?写偬曳熟及屈倖 case、及眉倖 case……匯稀窟孖才蝶倖屁侏方峙屢吉阻?祥氏峇佩朔中侭嗤議囂鞘。邪譜 m 才“屁侏方峙5”屢吉?椎担祥氏貫“囂鞘5”匯岷峇佩欺“囂鞘n+1”。

4) 泌惚岷欺恷朔匯倖“屁侏方峙n”脅短嗤孀欺屢吉議峙?椎担祥峇佩 default 朔議“囂鞘 n+1”。

俶勣嶷泣膿距議頁?輝才蝶倖屁侏方峙謄塘撹孔朔?氏峇佩乎蛍屶參式朔中侭嗤蛍屶議囂鞘。箭泌?

#include <stdio.h>
int main(){
 int a;
 printf("Input integer number:");
 scanf("%d",&a);
 switch(a){
 case 1: printf("Monday\n");
 case 2: printf("Tuesday\n");
 case 3: printf("Wednesday\n");
 case 4: printf("Thursday\n");
 case 5: printf("Friday\n");
 case 6: printf("Saturday\n");
 case 7: printf("Sunday\n");
 default:printf("error\n");
 }
 return 0;
}

塰佩潤惚?
Input integer number:4?L
Thursday
Friday
Saturday
Sunday
error

補秘4?窟孖才及膨倖蛍屶謄塘撹孔?噐頁祥峇佩及膨倖蛍屶參式朔中議侭嗤蛍屶。宸?堡参司芭卉馬誨ź捗畊菪n卉馬M蛺志莞亠數銚檥嶽Вii疒璘鍉鹵羌墜篷蔯嶽АNŃ亡鏥春盡歧娠蝪?慚誨ř效晋檥嶽ё邵麑躰?break;囂鞘。

break 頁C囂冱嶄議匯倖購囚忖?廨壇喘噐柳竃 switch 囂鞘。侭僚“柳竃”?頁峺匯稀囑欺 break?祥音壅峇佩 switch 嶄議販採囂鞘?淫凄輝念蛍屶嶄議囂鞘才凪麿蛍屶嶄議囂鞘?匆祥頁傍?屁倖 switch 峇佩潤崩阻?俊彭氏峇佩屁倖 switch 朔中議旗鷹。

聞喘 break 俐個貧中議旗鷹?

#include <stdio.h>
int main(){
 int a;
 printf("Input integer number:");
 scanf("%d",&a);
 switch(a){
 case 1: printf("Monday\n"); break;
 case 2: printf("Tuesday\n"); break;
 case 3: printf("Wednesday\n"); break;
 case 4: printf("Thursday\n"); break;
 case 5: printf("Friday\n"); break;
 case 6: printf("Saturday\n"); break;
 case 7: printf("Sunday\n"); break;
 default:printf("error\n"); break;
 }
 return 0;
}

塰佩潤惚?
Input integer number:4?L
Thursday

喇噐 default 頁恷朔匯倖蛍屶?謄塘朔音氏壅峇佩凪麿蛍屶?侭參匆辛參音耶紗break;囂鞘。

恷朔俶勣傍苧議曾泣頁?
1) case 朔中駅倬頁匯倖屁方?賜宀頁潤惚葎屁方議燕器塀?徽音嬬淫根販採延楚。萩心和中議箭徨?

case 10: printf("..."); break; //屎鳩
case 8+9: printf("..."); break; //屎鳩
case 'A': printf("..."); break; //屎鳩?忖憲才屁方辛參屢札廬算
case 'A'+19: printf("..."); break; //屎鳩?忖憲才屁方辛參屢札廬算
case 9.5: printf("..."); break; //危列?音嬬葎弌方
case a: printf("..."); break; //危列?音嬬淫根延楚
case a+10: printf("..."); break; //危列?音嬬淫根延楚

2) default 音頁駅倬議。輝短嗤 default 扮?泌惚侭嗤 case 脅謄塘払移?椎担祥焚担脅音峇佩。

<貧匯准和匯准>

C囂冱switch囂鞘

縮殻朕村