Characters after a space is not being printed out

user_13433212 0
Viewed 770

I was using character arrays to get inputs from the user then display the output afterwards. However, every time I enter values with spaces in between, only the first word before the space is printed.

For instance, this is what I typed:

Customer No.: 7877 323 2332

This will be the output:

Customer No.: 7877

I already searched for possible solutions but I can't seem to find the right solution.

This is my code for reference:

#include<iostream>
using namespace std;

int main()
{
    char custNum[10] = " ";  // The assignment does not allow std::string
    
    cout << "Please enter values for the following: " << endl;
    cout << "Customer No.: ";
    cin >> custNum;
    
    cout << "Customer No.: " << custNum << endl;
}
character limit char arrays c++
3 Answers

Another option is to use std::basic_istream::getline to read the entire string into the buffer and then remove the spaces with a simple for loop. But when using plain-old character arrays don't skimp on buffer size. It is far better to be 1000-characters too long than one-character too short. With your input, your absolute minimum size of custNum is 14 characters (the 13 shown plus the '\0' (nul-terminating) character. (rough rule-of-thumb, take your longest estimated input and double it -- to allow for user-mistake, cat stepping on keyboard, etc...)

In you case you can simply do:

#include <iostream>
#include <cctype>

int main() {
    
    char custNum[32] = " ";  // The assignment does not allow std::string
    int wrt = 0;
    
    std::cout << "Please enter values for the following:\nCustomer No.: ";
    
    if (std::cin.getline(custNum, 32)) {    /* validate every input */
    
        for (int rd = 0; custNum[rd]; rd++)
            if (!isspace((unsigned char)custNum[rd]))
                custNum[wrt++] = custNum[rd];
        custNum[wrt] = 0;
        
        std::cout << "Customer No.: " << custNum << '\n';
    }
}

The two loop counters rd (read position) and wrt (write position) are simply used to loop over the original string and remove any whitespace found, nul-terminating again when the loop is left.

Example Use/Output

$ ./bin/readcustnum
Please enter values for the following:
Customer No.: 7877 323 2332
Customer No.: 78773232332

Also take a look at Why is “using namespace std;” considered bad practice? and C++: “std::endl” vs “\n”. Much easier to build good habits now than it is to break bad ones later... Look things over and let me know if you have questions.

user_34221020

Apart from std::getline, if you are going to use C-style strings, try the following code:

int main() {
    char* str = new char[60];
    scanf("%[^\n]s", str);  //accepts space a a part of the string (does not give UB as it may seem initially
    printf("%s", str);
    return 0;
}

Also, if you absolutely need it to be a number, then use atoi

int ivar = std::atoi(str);

PS Not to forget gets (!!dangerous!!)

char* str;
gets(str);
puts(str);
user_119306020

cin >> int_variable will stop reading input when it reaches the first character that isn't a valid part of a number. C++ does not consider spaces part of a number, so it stops reading as soon as it encounters one.

You could use std::getline to read into a string instead, then remove the spaces from the string before converting to an integer. Or maybe in this case you don't even need the integer and can leave it as a string.

Mark_Ransom_59870
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