JavaScript: Variables and concatenation
To consolidate the previous topic, let's try using variables with concatenation. The syntax remains the same, we know how to concatenate (combine) two strings:
let what = 'Kings' + 'road';
console.log(what); // => 'Kingsroad'
… which means we can concatenate the string with a variable containing the string:
let first = 'Kings';
let what = first + 'road';
console.log(what); // => 'Kingsroad'
… and even concatenate two variables containing strings:
let first = 'Kings';
let last = 'road';
let what = first + last;
console.log(what); // => 'Kingsroad'
Instructions
Websites are constantly sending emails to their users. A common task is to automatically send a personalized email with the user's name in the header. If you store a person's name as a string somewhere in a website database, the task of generating the header boils down to concatenation. For instance, you have to concatenate the string Hello with a string containing their name.
Write a program that will create a header and a body of the email using ready-made variables and print the resulting strings.
For the header use the variables firstName and greeting, a comma, and an exclamation mark. Print it in the correct order.
For the email body, use the variables info and intro, with the second sentence on a new line.
The result should look like this:
Hello, Joffrey! Here is important information about your account security. We couldn't verify your mother's maiden name.
Complete the task using console.log() no more than twice.
Tips
Consider how you should concatenate the variables (Which string? What order?) to get the two-line output of the email body.
Remember that you can create a string containing only the escape sequence
\n.
The exercise doesn't pass checking. What to do? 😶
If you've reached a deadlock it's time to ask your question in the «Discussions». How ask a question correctly:
- Be sure to attach the test output, without it it's almost impossible to figure out what went wrong, even if you show your code. It's complicated for developers to execute code in their heads, but having a mistake before their eyes most probably will be helpful.
In my environment the code works, but not here 🤨
Tests are designed so that they test the solution in different ways and against different data. Often the solution works with one kind of input data but doesn't work with others. Check the «Tests» tab to figure this out, you can find hints at the error output.
My code is different from the teacher's one 🤔
It's fine. 🙆 One task in programming can be solved in many different ways. If your code passed all tests, it complies with the task conditions.
In some rare cases, the solution may be adjusted to the tests, but this can be seen immediately.
I've read the lessons but nothing is clear 🙄
It's hard to make educational materials that will suit everyone. We do our best but there is always something to improve. If you see a material that is not clear to you, describe the problem in “Discussions”. It will be great if you'll write unclear points in the question form. Usually, we need a few days for corrections.
By the way, you can participate in courses improvement. There is a link below to the lessons course code which you can edit right in your browser.
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Your exercise will be checked with these tests:
1// @ts-check
2
3import { expect, test, vi } from 'vitest'
4
5test('hello world', async () => {
6 const consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => { });
7 await import('./index.js')
8
9 const firstArg = consoleLogSpy.mock.calls.join('\n');
10
11 expect(firstArg).toBe("Hello, Joffrey!\nHere is important information about your account security.\nWe couldn't verify your mother's maiden name.")
12})
13Teacher's solution will be available in:
