可以用swich的case 語句結合來寫，而我認為數的判定方式有多種，在這裡，對於整數部分我們可以用將數值“三位為一組”來進行分！

如：678為第一組，前面加上 thousand

345為第二組，前面加上 million

依次為 billion

對於每組中的三個數分別含 百位 十位 個位

而小數點後面的則可以不用分位數，直接接對應的數！

下面是類似程式：

#include<stdio.h>

void main()

{

char *Eng1[20]={"zero","one","two","three","four","five","six","seven",

"eight","nine","ten","eleven","twelve","thirteen","fourteen","fifteen",

"sixteen","seventeen","eighteen","nineteen"};

char *Eng2[8]={"twenty","thirty","fourty","fifty","sixty","seventy","eighty","ninety"};

int num;

printf("請輸入數字: ");

scanf("%d",&num);

printf("對應的英文為: ");

if(num>=0&&num<=19)

printf("%s\n",Eng1[num]);

else if(num<100)

{

int s,y;

s=num/10;

y=num%10;

printf("%s %s\n",Eng2[s-2],Eng1[y]);

}

else if(num<1000)

{

int b,s,y;

b=num/100;

y=num%100;

if(y>9)

{

s=(num%100)/10;

y=(num%100)%10;

if(y==0)

printf("%s hundred and %s\n",Eng1[b],Eng2[s-2]);

else

printf("%s hundred and %s %s\n",Eng1[b],Eng2[s-2],Eng1[y]);

}

else

printf("%s hundred and %s\n",Eng1[b],Eng1[y]);

}

}