FTFY
The strike variant the AJ 37, was operational in -71, The fighter variant JA 37 in -79.
The AJS modification came in -92 giving the AJ 37, SF 37 (photo-recon) and SH 37 (maritme recon) limited multi-role capabilites.
The key word is limited. The first true multirole Saab is the Grippen. Unless you want to count the Saab MFI