Problem with scanf() when there is fgets()/gets()/scanf() after it
Consider below simple program in C. The program reads an integer using scanf(), then reads a string using fgets().
x = 10, str =
The problem with above code is scanf() reads an integer and leaves a newline character in buffer. So fgets() only reads newline and the string “test” is ignored by the program.
The similar problem occurs when scanf() is used in a loop.
a b q
......Enter q to quit...... Enter a character a Enter a character Enter a character b Enter a character Enter a character q
We can notice that above program prints an extra “Enter a character” followed by an extra new line. This happens because every scanf() leaves a newline character in buffer that is read by next scanf.
How to solve above problem?
- We can make scanf() to read a new line by using an extra “\n”, i.e., scanf(“%d\n”, &x) . In fact scanf(“%d “, &x) also works (Note extra space).
- We can add a getchar() after scanf() to read an extra newline.
This article is contributed by Dheeraj Gupta. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above