android ndk - cast jchar* to char*

why when casting jchar* to char* , c++ add a zero between each array element ?

java :

public char[] mychar; . . mychar = new char[3]; mychar[0] = 10; mychar[1] = 20; mychar[2] = 30; 

c++ :

Java_com_example_bb_mainact_getchar(JNIEnv *env, jobject thiz) { jclass cls = env->GetObjectClass(thiz); jfieldID fieldId = env->GetFieldID(cls, "mychar", "[C"); jobject objArray = env->GetObjectField (thiz, fieldId); jcharArray* chArray = reinterpret_cast<jcharArray*>(&objArray); jchar *data = env->GetCharArrayElements(*chArray, 0); LOGI( "data[0]: %d", data[0]); // --> 10 LOGI( "data[1] : %d", data[1]); // --> 20 LOGI( "data[2] : %d", data[2]); // --> 30 char* data2 = reinterpret_cast<char *>(data); LOGI( "data2[0] : %d", data2[0]); // --> 10 LOGI( "data2[1]: %d", data2[1]); // --> 0 LOGI( "data2[2]: %d", data2[2]); // --> 20 . 

why when cast from jchar* to char* c++ make array like this ? {10 , 0 , 20 , 0 , 30}