How to use merge() function In R Language

This function is used to join the dataframes based on the x parameter that specifies left join.

Syntax:

merge(dataframe1,dataframe2, all.x=TRUE)

where,

dataframe1 is the first dataframe
dataframe2 is the second dataframe

Example: R program to perform two dataframes and perform left join on name column

R

# create first dataframe
data1=data.frame('name'=c('siva','ramu','giri','geetha'),
                 'age'=c(21,23,21,20))
 
# display
print(data1)
 
# create second dataframe
data2=data.frame('name'=c('siva','ramya','giri','geetha','pallavi'),
                 'marks'=c(21,23,21,20,30))
 
# display
print(data2)
 
print("=========================")
 
# left join on name column
print(merge(data1, data2, by='name', all.x=TRUE))