char a = 1 vs char a ='1'java有什么区别

Question

I was trying one small program, Found this difference topic
public class TestA {
    public static void main(String[] args) {
        char c = 1;
        int a = c;
        System.out.println(a);
    }
}
public class TestB {
    public static void main(String[] args) {
        char c = '1';
        int a = c;
        System.out.println(a);
    }
}

当为c分配不同的值时发现了这种差异，想使用char将值存储在java中的方式