在项目中常用到一类数组，那就是不知道个数的数组，例如：
string ParamTable[] = {"frequency","ifbw","span","demodmode","afc","ifattmode","measuretime","detector", "gainctrl","mgcvalue","squelchthreshold","recordshold","holdtime","dweltime","keeptime","rfattenuation", "bandmode","xdb","betapercent","startfreq","stopfreq","step","scancount","levelrange", "reflevel","displaymode","preamplifier","dfmode","dfbw","integrationtime","freqrange","qualityshold", "levelshold","sholdlevel","rbw","vbw","sweeptime","polarization","modulation","antenna", "if_fq","fixfq","iqdem","sr_md" };
想得到里面元素的个数，也就是得到这个数组的维度，被困扰了很久，下面给出了一种办法，亲测有效
size_t words_size= sizeof(ParamTable)/sizeof(string);
这是用string的情况，下面是c语言的情况：
char *words[] = {"stately", "plump", "buck"}; size_t words_size = sizeof(words)/sizeof(char*);
原文：http://www.cnblogs.com/shmilxu/p/5056837.html