[C++] 알파벳 a-z ↔ 0-26 변환하는 방법 (int ↔ char)

1. char to int : char이 알파벳인 경우

	char c = 'a';
	int start0 = c - 'a'; // a = 0;
	int start1 = c - 'a' + 1; // a = 1;
	cout << "c : " << c << ", start0 : " << start0 << ", start1: " << start1 << endl;

출력값

c : a, start0 : 0, start1: 1

 

 

2. char to int : char이 숫자인 경우

 

	char a = '0';
	char b = '1';
	int i = a - '0';
	int j = b - '0' + 1;
	cout << "a : " << a <<", b :" << b << endl;
	cout<< "i : " << i << ", char(97 + i) : " << char(97 + i) << endl;
	cout << "j : " << j << ", char(97 + j) : " << char(97 + j) << endl;

출력값

a : 0, b :1
i : 0, char(97 + i) : a
j : 2, char(97 + j) : c

 

 

 

3. int to char

	char a = 0 + 'a';
	char b = 0 + 'a' + 1; 
	char c = 0 + 'a' + 2;
	cout << "print a : " << a << ", b : " << b << ", c: " << c << endl;

 

출력값

print a : a, b : b, c: c