| otherwise {SparkR} | R Documentation | 
If values in the specified column are null, returns the value.
Can be used in conjunction with when to specify a default value for expressions.
otherwise(x, value) ## S4 method for signature 'Column' otherwise(x, value)
| x | a Column. | 
| value | value to replace when the corresponding entry in  | 
otherwise since 1.5.0
Other colum_func: alias,
between, cast,
endsWith, over,
startsWith, substr