19.2: Numeric to Character String Conversion
- Page ID
- 54385
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An integer or real value can be converted into a character string using a write operation. The string is provided as the output variable instead of a file unit number. The numeric variable is provided as the input for the write operation.
The following is a simple example that will convert an integer into a string and a real into a string. Some numeric operations are performed on the numeric values and then the resulting strings are concatenated with another string. Concatenation can only be performed on character data types.
! Example program to use an internal write for
! character / numeric conversion.
program cvtExample2
implicit none
integer :: cvtErr
character(50) :: str1, str2, msg1, msg2
integer :: iNum=2468
real :: pi = 3.14, tau
write (*,'(a, /)') "Example Conversion Program."
! ----------
! Convert integer value to a string.
iNum = iNum / 100
write (str1, '(i3)', iostat=cvtErr) iNum
if (cvtErr == 0 ) then
msg1 = "My age is " // str1
write (*,'(a, a)') &
"Message 1 = ", msg1
else
write (*,'(a, /)') "Error, invalid conversion."
end if
! ----------
! Convert real value to a string.
tau = pi * 2.0
write (str2, '(f5.3)', iostat=cvtErr) tau
if (cvtErr == 0 ) then
msg2 = "The value of TAU is " // str2
write (*,'(a, a, /)') &
"Message 2 = ", msg2
else
write (*,'(a, /)') "Error, invalid conversion."
end if
end program cvtExample2
An example of the output for this program is as follows:
Example Conversion Program. Message 1 = My age is 124 Message 2 = The value of TAU is 6.283
Once the numeric values are converted into strings, the character functions and character operations can be used as needed.