R version 4.5.2 (2025-10-31 ucrt) -- "[Not] Part in a Rumble"
Copyright (C) 2025 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> x -> 5
Error in 5 <- x : invalid (do_set) left-hand side to assignment
> 5 -> x
> x
[1] 5
> TRUE <- 10
Error in TRUE <- 10 : invalid (do_set) left-hand side to assignment
> sklhadfawoir <- 100
> x1 <- 100
> ls()
[1] "sklhadfawoir" "x"            "x1"          
> getwd()
[1] "C:/Users/user/Documents"
> setwd('C:/Users/user/Documents/Project1')
> getwd()
[1] "C:/Users/user/Documents/Project1"
> 
> ?mean   #calling help on 'mean'
starting httpd help server ... done
> ?rivers
> 

> rivers
  [1]  735  320  325  392  524  450 1459  135  465  600  330  336  280  315  870
 [16]  906  202  329  290 1000  600  505 1450  840 1243  890  350  407  286  280
 [31]  525  720  390  250  327  230  265  850  210  630  260  230  360  730  600
 [46]  306  390  420  291  710  340  217  281  352  259  250  470  680  570  350
 [61]  300  560  900  625  332 2348 1171 3710 2315 2533  780  280  410  460  260
 [76]  255  431  350  760  618  338  981 1306  500  696  605  250  411 1054  735
 [91]  233  435  490  310  460  383  375 1270  545  445 1885  380  300  380  377
[106]  425  276  210  800  420  350  360  538 1100 1205  314  237  610  360  540
[121] 1038  424  310  300  444  301  268  620  215  652  900  525  246  360  529
[136]  500  720  270  430  671 1770
> help(var)
> ?+

+ > ?'+'
> ls()
[1] "sklhadfawoir" "x"            "x1"          
> history()
> a <- (3+5)^(1+1.5
+ )
> a
[1] 181.0193
> hist(rivers)    #note this is a graphics command 
> mean(rivers)
[1] 591.1844
> hist(rivers)
> boxplot(rivers)
> 



NOW ON in RStudio
R version 4.5.2 (2025-10-31 ucrt) -- "[Not] Part in a Rumble"
Copyright (C) 2025 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> x <- 10
> y <- 20
> z <- x+y
> a <- (3+5)^((1+1.5))
> ?help
> mean(rivers)
[1] 591.1844
> hist(rivers)
> boxplot(rivers)
> rm(z,y)   #deletes variables z and y 
> z
Error: object 'z' not found

> 
> 
> #to remove all variables at once we type:
> rm(list=ls())     
> 
> 
> 15 %% 4 
[1] 3
> 
> 15 %/% 4 
[1] 3
> 
> 20 %% 4
[1] 0
> 20 %/% 4
[1] 5
> 15/4
[1] 3.75
> 
> 
> 5 * 4    #arithmetic operator
[1] 20
> 5 > 4    #logical operator
[1] TRUE
> 5 == 4  #another logical operator n
[1] FALSE
> 5 = 4 
Error in 5 = 4 : invalid (do_set) left-hand side to assignment

> 
> log(0)
[1] -Inf
> 
> #special values in R 
> b <- NA
> c <- MA
Error: object 'MA' not found

> rivers1.10 <- rivers[1:10]
> rivers1.10
 [1]  735  320  325  392  524  450 1459  135  465  600
> rivers1.10[c(1,5)] <- NA
> rivers1.10
 [1]   NA  320  325  392   NA  450 1459  135  465  600
> mean(rivers1.10)
[1] NA
> log(-1)
[1] NaN
Warning message:
In log(-1) : NaNs produced

> 0/0
[1] NaN
> rivers1.10[3] <- nan
Error: object 'nan' not found

> rivers1.10[3] <- NaN
> rivers1.10
 [1]   NA  320  NaN  392   NA  450 1459  135  465  600
> rivers1.10[8] <- Inf
> rivers1.10
 [1]   NA  320  NaN  392   NA  450 1459  Inf  465  600
> 
> 
> #order of operations
> 5+3*4 
[1] 17
> (5+3)*4 
[1] 32
> 5 == 4  #another logical operator n
[1] FALSE
> 10*(5 == 4)
[1] 0
>