How to Merge DataFrames Based on Multiple Columns in R?

# create dataframe1
data1 = data.frame(name=c("manoj", "manoja", "saroja", "ramya"),
                   subjects=c("java", "c/cpp", "python", "R"),
                   city=c("ponnur", "tenali", "hyd", "guntur"),
                   marks=c(89, 90, 78, 89))

# create dataframe2
data2 = data.frame(name=c("manoj", "sravya", "saroja", "pavani"),
                   subjects=c("java", "c/html", "python", "php/css"),
                   city=c("ponnur", "hyd", "hyd", "guntur"),
                   marks=c(89, 78, 78, 81))

# display
print(data1)
print(data2)

# create dataframe1
data1 = data.frame(name=c("manoj", "manoja", "saroja", "ramya"),
                   subjects=c("java", "c/cpp", "python", "R"),
                   city=c("ponnur", "tenali", "hyd", "guntur"),
                   marks=c(89, 90, 78, 89))

# create dataframe2
data2 = data.frame(student=c("manoj", "sravya", "saroja", "pavani"),
                   subjects=c("java", "c/html", "python", "php/css"),
                   city=c("ponnur", "hyd", "hyd", "guntur"),
                   exams=c(89, 78, 78, 81))

# merge dataframes based on name and subjects from data1
# with student and subjects from data2
merge(data1, data2, by.x=c('name', 'subjects'),
      by.y=c('student', 'subjects'))

# create dataframe1
data1 = data.frame(name=c("manoj", "manoja", "saroja", "ramya"),
                   subjects=c("java", "c/cpp", "python", "R"),
                   city=c("ponnur", "tenali", "hyd", "guntur"),
                   marks=c(89, 90, 78, 89))

# create dataframe2
data2 = data.frame(student=c("manoj", "sravya", "saroja", "pavani"),
                   subjects=c("java", "c/html", "python", "php/css"),
                   city=c("ponnur", "hyd", "hyd", "guntur"),
                   exams=c(89, 78, 78, 81))

# merge dataframes based on name,city and subjects from data1
# with student,city and subjects from data2
merge(data1, data2, by.x=c('name', 'subjects', 'city'),
      by.y=c('student', 'subjects', 'city'))