What is apply() in Clojure?
Clojure is a modern parallel programming language that operates on the Java Virtual Machine (JVM), the common language runtime (CLR), and JavaScript engines.
The apply() function
The apply() function in Clojure allows you to call a function with various arguments. It takes a function and a list of arguments, and then it applies the function to the arguments in the list.
The apply() function comes in handy when you have a collection of arguments to provide to a function and don't want to manually extract and pass each parameter.
Syntax
The syntax of the apply function is given below:
(apply function arguments)
functionis a required parameter and is the function that you want to apply.argumentsis a required parameter showing a list of arguments you want to pass to the function.
Code
Let's go through a basic code example that implements the apply() function in Clojure:
(def numbers [1 2 3 4 5])(defn sum-of-numbers [nums](apply + nums))(def total-sum (sum-of-numbers numbers))(println "Total Sum:" total-sum)
Code explanation
Line 1: Firstly, we define a list of numbers
[1 2 3 4 5]and store it in the variablenumbers.Line 3–4: Next, we define a function
sum-of-numbersthat takes the argumentnumsand uses theapplyfunction to calculate the sum of the numbers in thenumslist using the+operator.Line 6: Now, we call the
sum-of-numbersfunction with thenumberslist as its argument and store the result in thetotal-sumvariable.Line 8: Finally, we print the total sum using the
printlnfunction.
Conclusion
Therefore, the apply() function in Clojure is a flexible tool for invoking functions with various parameters. It simplifies giving a collection of arguments to a function, making your code more compact and readable. Developers leverage Clojure's functional programming model and build clean, efficient, and expressive code by knowing and efficiently using the apply() function.
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