Hello Splunkers, 
I have case field with below information so i need to construct Eval field. 
case**
XYZ
2
0
3
yzr 
Now i have to construct eval field like
If case=string then print case as it was in case field
    case=2 then print " error code 2"
    case =3 the print " error code 3"
    case=0  then " error zero "
 
					
				
		
Try this
| makeresults 
| eval temp="XYZ,2,0,3,yzr" 
| eval temp = split(temp,",") 
| mvexpand temp 
| eval status = case (temp=2 ,"error code 2 ", temp=3 ,"errorcode 3",temp = 0 , "error code 0",if(isstr(temp),"yes","no")=="yes" ,temp)
 
					
				
		
Try this
| makeresults 
| eval temp="XYZ,2,0,3,yzr" 
| eval temp = split(temp,",") 
| mvexpand temp 
| eval status = case (temp=2 ,"error code 2 ", temp=3 ,"errorcode 3",temp = 0 , "error code 0",if(isstr(temp),"yes","no")=="yes" ,temp)
Thanks but that will not fulfill my req i need add Eval field to props file based on output.
 
					
				
		
You can use this in caluclated fields in props.conf by specifying like this
EVAL-status = case (temp=2 ,"error code 2 ", temp=3 ,"errorcode 3",temp = 0 , "error code 0",if(isstr(temp),"yes","no")=="yes" ,temp)
 
					
				
		
Minor cosmetic correction:
EVAL-status = case (temp=2 ,"error code 2 ", temp=3 ,"errorcode 3",temp = 0 , "error code 0",isstr(temp), ,temp)
Thanks somesoni & ssadanala1 it worked for me now.
