Some common output about sizeof and strlen
(ubuntu 18.04 64bit) sizeof(char) = 1 sizeof(char*) = 8 sizeof(int) = 4 sizeof(int*) = 8 sizeof(long) = 8 sizeof(long*) = 8 sizeof(double) = 8 sizeof(double*) = 8 char a[]="hello"; char b[]={'h', 'e', 'l', 'l', 'o', 'w', 'o', 'r', 'l', 'd'}; char *c="abcdef"; char d[]="abcdef"; char e[]={'a','b','c','d','e','f'}; sizeof(a) = 6, strlen(a) = 5 sizeof(b) = 10, strlen(b) = 10 sizeof(c) = 8, strlen(c) = 6 sizeof(d) = 7, strlen(d) = 6 sizeof(e) = 6, strlen(e) = 12
//...(more)