Lua中算术运算符的使用示例（lua计算字符串长度）怎么可以错过

a=21

b=10

c=a + b

print(“Line 1 – Value of c is “, c )

c=a – b

print(“Line 2 – Value of c is “, c )

c=a * b

print(“Line 3 – Value of c is “, c )

c=a / b

print(“Line 4 – Value of c is “, c )

c=a % b

print(“Line 5 – Value of c is “, c )

c=a^2

print(“Line 6 – Value of c is “, c )

c=-a

print(“Line 7 – Value of c is “, c )