#include<stdio.h>  #include<stdlib.h>  int main()  {      int a=2013420;      float b=2.054f;      double c=5.24;      char sa[20],sb[20],sc[20];      //将整数a转换为字符串      itoa(a,sa,10);      puts(sa);      //将浮点型数据转换为字符串      sprintf(sb,"%g",b);      puts(sb);      //将double型数据转换为字符串      sprintf(sc,"%lg",c);      puts(sc);      printf("========以下是串转换为数值=========\n");      char *s1="123",*s2="1.23";      printf("%d\n",atoi(s1));      printf("%g\n",atof(s2));      getchar();      return 0;  }