This code snippet code install packages if it does not exist

Check and install R package

Clear all variables in work space and install packages

```{r message = FALSE,warning = FALSE}
# Clears environment
rm(list=ls())

# Add packages needed in the project
requiredPackages = c('quantmod','TTR','tseries')

for(p in requiredPackages){
  if(!require(p,character.only = TRUE)) install.packages(p) # Install package if it does not exist
  library(p,character.only = TRUE)
}

```

Alternative Method 2:

# Package names
packages <- c("ggplot2", "readxl", "dplyr", "tidyr", "ggfortify", "DT", "reshape2", "knitr", "lubridate")

# Install packages not yet installed
installed_packages <- packages %in% rownames(installed.packages())
if (any(installed_packages == FALSE)) {
  install.packages(packages[!installed_packages])
}

# Packages loading
invisible(lapply(packages, library, character.only = TRUE))

Alternative Method 3:

install.packages("pacman")
pacman::p_load(ggplot2, tidyr, dplyr)