CODEWITHSUNDEEP
c++ifstream
M.A
M.A

Reputation: 1133

File input and process data

I would like to read from a text file and the format of the file is

Method 1
Method 2
Insert 3 "James Tan"

I am currently using ifstream to open the text file and read the items, but when I use >> to read the lines, which is causing the name not to be fully read as "James Tan". Attached below is the code and the output.

ifstream fileInput; 

  if(fileInput.is_open()){
       while(fileInput.good()){
  fileInput >>methondName>>value>>Name;
    ......

Output

methodName = Method, Method, Insert
value = 1, 2, 3 (must be a usigned integer)
Name = James

What is the better way to process the reading of the lines and the contents. I was told about getline. But i understand that getline reads fully as a line rather than a single word by single word.

Next is fstream really fast?. cause, I would like to process 500000 lines of data and if ifstream is not fast, what other options do I have.

Please advice on this.

Upvotes: 0

Views: 789

Answers (1)

Robᵩ
Robᵩ

Reputation: 168626

Method 1
Method 2
Insert 3 "James Tan"

I take it you mean that the file consists of several lines. Each line either begins with the word "Method" or the word "Insert", in each case followed by a number. Additionally, lines that begin "Insert" have a multi-word name at the end.

Is that right? If so, try:

ifstream fileInput("input.txt");
std::string methodName;
int value;
while ( fileInput >> methodName >> value ) {
  std::string name;
  if(methodName == "Insert")
    std::getline(fileInput, name);

  // Now do whatever you meant to do with the record.
  records.push_back(RecordType(methodName, value, name); // for example
}

Upvotes: 3

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