这个代码里面的&是取地址符还是位与

#include <jni.h>
#include <string>
static const char base64en[] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f','g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
extern "C" JNIEXPORT jstring JNICALL
Java_com_kanxue_basc64demo_MainActivity_stringFromJNI(
JNIEnv* env,
jobject /* this */) {
std::string hello = "Hello from C++";
return env->NewStringUTF(hello.c_str());
}
void base64_enc(const char *data,char *out){
int len_data=strlen(data);
int index=0;
char last_c='\0';
for (int i = 0; i < len_data ;++i) {
char c=data[i];
switch (i%3) {
case 0:
out[index++]=base64en[(c>>2)&0x3f];
break;
case 1:
out[index++]=base64en[((last_c&0x3)<<4)|((c>>4)&0xf)];
break;
case 2:
out[index++]=base64en[((last_c&0xf)<<2)|((c>>6)&0x3)];
out[index++]=base64en[c&0x3f];
break;
}
last_c=c;
}
}
extern "C" JNIEXPORT jstring JNICALL
Java_com_kanxue_basc64demo_MainActivity_basc64enc(
JNIEnv* env,jobject thiz,jstring str666666
) {
const char *data=env->GetStringUTFChars(str666666,NULL);
char out[100]={0};
base64_enc(data,out);
env->NewStringUTF(out);
}