Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
We are required to write a JavaScript function that takes in two strings and concatenates the second string to the first string.If the last character of the first string and the first character of the second string are the same then we have to omit one of those characters.ExampleThe code for this will be −const str1 = 'Food'; const str2 = 'dog'; const concatenateStrings = (str1, str2) => { const { length: l1 } = str1; const { length: l2 } = str2; if(str1[l1 - 1] !== str2[0]){ return str1 + str2; }; ... Read More
We are required to write a JavaScript function that takes in a number and returns a boolean based on the fact whether or not the number is a perfect square.Examples of perfect square numbers −Some perfect square numbers are −144, 196, 121, 81, 484ExampleThe code for this will be −const num = 484; const isPerfectSquare = num => { let ind = 1; while(ind * ind
We are required to write a JavaScript function that takes in an array of numbers and returns the cumulative sum of every number present at the index that is a multiple of n from the array.ExampleThe code for this will be −const arr = [5, 3, 5, 6, 12, 5, 65, 3, 2]; const num = 3; const nthSum = (arr, num) => { let sum = 0; for(let i = 0; i < arr.length; i++){ if(i % num !== 0){ continue; }; sum += arr[i]; }; return sum; }; console.log(nthSum(arr, num));OutputThe output in the console −76
To create a line chart in base R using plot function, we need to use type = "l" so that R understand the plot needs to have a line instead of points. If we want to increase the width of the line then lwd argument can be used. The value lwd = 0 is the default value for the width.Consider the below vector and create the line chart −Examplex
The plot area in plot window is fixed by default and we can create a lint chart with extended width so that the chart covers the area of the plot from bottom left to upper right. This can be done by using very large width of the line chart with the help of lwd argument.Consider the below vector and create the very wide line chart to cover the plot area −Examplex
The barplot function create the bars of equal width but if we have equal or unequal width values for each bar then we can use width within the barplot function. Thus, the newly generated barplot will have different width of the bars. For example, if we the width are defined for four categories as 0.25 each then each bar will be of equal width and if they vary as 0.30, 0.40, 0.20, 0.45 then the width of the bars will be different based on these widths.Consider the below vector x and the corresponding width vector −x
When we create boxplots for multiple categories in R using boxplot function, by default the X-axis labels are represented by numbers. But we might want to express the categories by their name. In this situation, we can use names argument along with the boxplot function.Consider the below vectors that represent different categories and create the boxplot for these categories −ExampleClass1
Although, the histogram represents the distribution of a complete set of values but we might want to visualize that histogram based on the division of some threshold value. For example, we might want to visualize the histogram with different bars that have values greater than 1 or less than 1. This will help us to understand the distribution of the values in whole data set that lies above or below certain value. For this purpose, we can simply use hist function with col argument to change the color of the values that are greater than or less than a fixed ... Read More
The residual variance is the variance of the values that are calculated by finding the distance between regression line and the actual points, this distance is actually called the residual. Suppose we have a linear regression model named as Model then finding the residual variance can be done as (summary(Model)$sigma)**2.Examplex1
In general, the scatterplot is used to visualize the relationship between two columns of an R data frame but if we want to display the two columns separately not as a pair then we need to use matplot function. This function will create a plot for all the values in the two columns and represent them by their column number.Consider the below data frame −Example Live Demoset.seed(222) x