目的：在打印字符串后自动换行
ex1:
b ='what is value？n';
a = input(b)；
y = a*10；
命令行显示结果
what is value
10
a =
10
y =
100
>> 这里的换行符是n,不是/n.
ex2:
b ='what is valuen';
a = input(b);
y = a*10;
disp(y);
命令行显示结果
what is value
20
200
eg3:
x = input('input x plasen');
y = input('input y plasen');
z = x;
x = y ;
y = z ;
disp('x is');
disp(x);
disp('y is');
x = y ;
y = z ;
disp('x is');
disp(x);
disp('y is');
disp(y);
命令行显示结果
input x plase
60
input y plase
50
x is
50
y is
60