判断字符串是否为标准IP地址

+(BOOL) isIPAdress :(NSString *)ip{

NSArray *array = [ip componentsSeparatedByString:@"."];
NSLog(@"number of array %ld",[array count]);
for (NSString *sIP in array) {
NSLog(@"%@",sIP);
}
BOOL flag = YES;
if ([array count] == 4) {//判断是否为四段
for (int i = 0; i<4; i++) {
//判断是否由数字组成
const char *str = [array[i] cStringUsingEncoding:NSUTF8StringEncoding];
int j = 0;
while (str[j] != '\0' ) {
if (str[j] >= '0' && str[j] <= '9') {
j++;
}else{
flag = NO;
break;
}
}
//判断ip是否在0-255范围中
if (flag) {
NSInteger temp = [array[i] integerValue];
if (temp < 0 || temp > 255) {
flag = NO;
break;
}
}
}
}else{
flag = NO;
}
return flag;
}