C ++ primer plus Study Notes (5)

1. logical expressions

1. | the operator is a sequence point ).

First, modify the value on the left and then judge the value on the right. For example, I ++ <6 | I = J

First I ++ and then I = J;

2. The priority of the & operator is lower than that of the relational operator.

2. Simple file input and output

Assume that the following example is input: 38.5 19.2

1. Char ch; CIN> CH

The encoding of character 3 is not stored here.

2. Int N; CIN> N;

Cin will continue to read until non-numeric characters are encountered. For example, click. Here.

3. Char word [50]; CIN> word;

Here, the CIN is continuously read until blank characters are encountered.

4. Char word [50]; cin. Getline (word, 50 );

Here, CIN keeps reading until a line break is encountered.

3. file output operation steps:

1. Declare An ifstream variable (object ). Associate objects with files. For example, open ().

2. You can use the ifstream object and operator <to read various types of data.

3. You can use an ifstream object and get () to read a single character and use Getline () to read a row.

4. Check whether the input is successful by combining EOF () and fail.

5. Good () checks whether an error occurs, such as EOF or file downloading.