In Fortran, READ(*,*) and WRITE(*,*) are input/output statements that allow you to read data from and write data to the standard input/output channels (keyboard/output screen).
Here’s a simple explanation of these statements:
1. READ(*,*)
This statement is used to read input data from the standard input (usually the keyboard) into variables.
- The
*in the first position denotes that the input is coming from the default input channel (such as keyboard) - The second
*denotes that the format of the input is unspecified. It means that the program reads the input as a list of values and assigns them to the specified variables.
Example:
In the below code, the program will read an integer value from the standard input and assign it to the variable age.
INTEGER :: age READ(*,*) age
2.WRITE(*,*)
This statement is used to write output data to the standard output (usually the console or terminal).
- The
*in the first position indicates that the output is directed to the default output channel (such as your screen). - The second
*indicates that the format of the output is unspecified. It means that the program writes the values of the specified variables as a list to the standard output.
Example:
In the below code, the program will write a message and the value of the variable temperature to the standard output, displaying something like: “The current temperature is: 25.5”.
REAL :: temperature = 25.5 WRITE(*,*) "The current temperature is:", temperature