In programming and coding dynamic web pages comparisons between values of variables become essential.
Conditional operators are special operators which assign a value / variable based on the result of the condition.
With the comparison operators, it’s general comparison of equality or difference. We’ll illustrate the types of comparison and logical operators in the following tables.
|=||==||X == Y||X is equal to Y|
|≠||!=||X != Y||X is not equal to Y|
|>||>||X > Y||X is greater than Y|
|<||<||X < Y||X is less than Y|
|≥||>=||X >= Y||X is greater than or equal to Y|
|≤||<=||X <= Y||X is less than or Equal to Y|
|AND||&&||X < 12 && Y > 20||X is less than 12 AND Y is greater than 20|
|OR||||||X > 15 || Y > 20||Either X is greater than 15 OR Y is greater than 20|
|NOT||!||!(X < Y)||It is not that X is less than Y|
Conditional Operator Syntax
The syntax for the conditional operators is
If the ‘condition’ is true then, the ‘value1’ is assigned to variable_name otherwise, ‘value2’ is assigned.
You can create complex conditions by combining comparison operators and logical operators such as
&& (logical AND) and
|| (logical OR).
Using Logical AND (&&)
In this example, both conditions (
age >= 18 and
hasLicense) must be
true for the message “You can drive!” to be displayed.
Using Logical OR (||)
true is enough to trigger the “It’s time to relax!” message.
Comparison Operator Example
The example below will give you deeper understanding about the working of these operators.
It uses four if statements to display a time-sensitive greeting on a welcome page. The script obtains local time from the user’s computer and converts it to a 12-hour clock format. The script wishes you “Good Morning” in the morning and “Good Evening” in the Evening.
1. Use Strict Equality
To avoid this, it is recommended to use the strict equality ( === ) and strict inequality ( !== ) operators whenever possible. These operators compare values without performing type coercion, which can help ensure that the comparison is accurate and predictable.
For example, consider the following code:
In the second line, the strict equality operator is used instead. Since this operator does not perform type coercion, the comparison returns false since the number 5 is not equal to the string ‘5’.
By using the strict equality and strict inequality operators, you can avoid unexpected type coercion and ensure that your code behaves predictably.
2. Be Explicit
When writing code, it is important to clearly state your intentions. This means making your code easy to understand and interpret by others, including your future self. One way to achieve this is by using comments to explain complex conditions and comparisons.
Comments are lines of code that are not executed by the program but serve as explanations or annotations for the code. They provide additional context and clarification for parts of the code that may be difficult to understand at first glance.
When dealing with complex conditions or comparisons, it is helpful to include comments that explain the logic behind them. This can make it easier for other programmers to follow the code and understand the reasoning behind specific decisions or calculations.
For example, if you have a complex if statement with multiple conditions, you can use comments to break down each condition and explain its purpose. This can help other programmers understand the logic flow and make it easier to debug or modify the code in the future.
It is also important to use meaningful variable and function names that accurately reflect their purpose. This can make the code more self-explanatory and reduce the need for excessive comments.
However, it is worth noting that while comments can be helpful, they should not be used as a substitute for writing clear and concise code. Strive to write code that is self-explanatory and easy to understand without relying heavily on comments.
3. Test Edge Cases
Testing code is an essential part of the software development process. It involves running the code with various inputs to ensure that it behaves as expected. This helps identify bugs and errors in the code, and ensures that the code is functioning correctly.
When testing code, it’s important to consider edge cases. An edge case is a scenario that is unlikely to occur, but still possible. For example, if you’re writing a program that calculates the average of a list of numbers, an edge case would be an empty list or a list with only one number.
By testing edge cases, you can ensure that your code is robust and able to handle unexpected scenarios. This can help prevent errors and bugs in the code, and make your code more reliable.
There are several types of tests that can be performed on code, including unit tests, integration tests, and acceptance tests. Each type of test serves a different purpose and can help ensure that your code is functioning correctly.
Consistent coding conventions are a set of guidelines that programmers follow while writing code. Adhering to these conventions within a team or project can greatly improve code readability.
Code readability refers to how easy it is to understand and interpret the code. When code is written in a consistent manner, it becomes easier for other programmers to read and understand it. This can save time and effort, especially when working on large projects with multiple team members.
Some common coding conventions include naming conventions, indentation, commenting, and formatting. By following these conventions, the code becomes more organized and easier to navigate. Additionally, it can help prevent errors and bugs in the code.