How to apply a chunk of code (not only a single function) to all columns in dataset - r

Question

I would like to apply this chunk of code to each column in a dataset. I can run all columns individually, but it is tedious to make repeated code for 75 different columns and change all of the names in the code to match each column name. Is there a way that I can run all columns individually at once without making code for each column individually?
max.Width =lmer(mergeCowpeaTEST$max.Width ~ (1|Genotype) + (1|Year) + (1|Genotype:Year) + (1|Rep:Year), data=mergeCowpeaTEST,na.action = na.omit)
model.a_max.Width <-lmer(max.Width~ (1|Genotype) + (1|Year) + (1|Genotype:Year) + (1|Rep:Year), data=mergeCowpeaTEST)
alt.est.a_max.Width <- influence(model.a_max.Width, obs=TRUE)
cooks<-cooks.distance(alt.est.a_max.Width)
plot(alt.est.a_max.Width, which="cook", sort=FALSE,main="cook's distance plot of max.Width")
which(residuals(max.Width)>0.10)
which(residuals(max.Width)<(-0.10))
boxplot(residuals(max.Width))
myboxplot<-boxplot(residuals(max.Width))
myboxplot$out
hist(residuals(max.Width))
qqnorm(residuals(max.Width))
pdf("Widiv_max.Width_residual_graphs.pdf",height=8,width=10)
plot(fitted(max.Width),residuals(max.Width), xlab="Predicted values", ylab="Residuals", main="Residual Plot of widiv max.Width")
abline(h=0, col="red")
hist(resid(max.Width),main="histogram of max.Width residuals")
qqnorm(residuals(max.Width), main="Residuals Q-Q Plot");qqline(resid(max.Width))
qqnorm(ranef(max.Width)$Genotype$"(Intercept)", main="Genotypes Q-Q Plot"); qqline(ranef(max.Width)$Genotype$"(Intercept)")
qqnorm(ranef(max.Width)$"Genotype:Year"$"(Intercept)", main="Genotype by Year Q-Q Plot"); qqline(ranef(max.Width)$"Genotype:Year"$"(Intercept)")
plot(alt.est.a_max.Width, which="cook", sort=FALSE,main="cook's distance plot of max.Width")
dev.off()

Answer 1

The key to this is your describing it as "only" a single function. A single function can run an arbitrary amount of things. You can have it print something, then do something, then output something. Or do lots of things. Or play Global Geothermonuclear War. All in a single function.
apply( ChickWeight, 2, function(clmn) {
cat("Hi")
cat("Low")
cat("The only way to win is not to play at all")
} )