1. Priority: Different mathematical operators have different priorities. Multiplication and division take precedence over addition and subtraction. When calculating an expression, it needs to be calculated according to the priority of the operator.
2. Combination: Combine some mathematical operators, that is, calculate from left to right; Some operators have right-to-left combinations. For example, addition and subtraction are combined on the left and multiplication and division are combined on the right.
3. Parentheses: Parentheses can change the operation order, so that the expressions in parentheses are calculated first. In complex expressions, using parentheses can help us clearly express the calculation order.
4. Unary operator: Unary operator has only one operand, such as positive sign (+), negative sign (-) and absolute value sign (abs). When using unary operators, we need to pay attention to their scope of action.
5. Binary operators: Binary operators have two operands, such as addition, subtraction, multiplication and division. When using binary operators, you need to pay attention to whether the types and quantities of operands match.
6. Overflow: In numerical calculation, we need to pay attention to the problem of data type overflow. For example, the addition of two large integers may lead to integer overflow and get the wrong result. In this case, you can use a wider range of data types or check for overflow.
7. floating point precision: when calculating floating point numbers, we need to pay attention to the precision of floating point numbers. Because of the limited ways to express floating-point numbers in computers, rounding errors may occur in floating-point number calculation. In order to reduce the error, a suitable algorithm or library function can be used for calculation.
8. Logical Operator: A logical operator is used to compare two Boolean values (true or false) and return a Boolean value. When using logical operators, we need to pay attention to the types and logical relationships of operands.
9. Bitwise operator: Bitwise operators are used to operate binary numbers, such as bitwise AND, bitwise OR and bitwise XOR. When using bit operators, you need to pay attention to the types and digits of operands.
10. Mathematical function: In mathematical calculation, you can use mathematical functions to simplify the code. When using mathematical functions, we need to pay attention to the parameter types and return value types of the functions.