Javascript number in function name

how to append a number to a function name to create many functions?

i ve a function which is responsible for some validations, disabling and enabling of some text boxes and a group of radio buttons . now i want to generate the function name to be called from another function using a for loop and then appending the for loop index to the function in question . something like this .

function unCheckRadio(num) < var cont = num; var form = document.angular; for (var i = 0; i < cont; i++) < alert(form['lim_set'+i].length); for(var j = 0; j < form['lim_set'+i].length; j++ ) < form['lim_set'+i][j].checked = form['lim_set'+i][j].defaultChecked; >makeChoice_ang(); > > 

here i want to append the index i to the makeChoice_ang() function . tried many ways . but no go . i tried using this . ‘makeChoice_ang’+i; but this is making it an string . Please help me out or atleast point me in the right direction . Thanks a million in advance !!

5 Answers 5

I’m adding this as a different answer because, well, it’s different!

If you want to call a global function (or any function you know the scope of) given a suffix like that, then you could just use array notation:

Thanks a heap nick . worked like a charm . thanks to all others too . i couldn’t use arrays thats why i was in this fix . i should have mentioned that . Thanks a ton to stack overflow

It seems like it would be easier to re-do makeChoice_ang() as a generic function that accepts an index as a parameter. Alternatively, if you can’t change the function or if the behavior will vary wildly from function to function you could just use eval() to evaluate your string.

Make an object to put your functions into. Make a method in this object for each ‘makeChoice_ang’+i function. You can then call these functions through that object.

var f = < makeChoice_ang1: function()< alert('1'); >, makeChoice_ang2: function() < alert('2'); >> for(var i = 1; i < 3;i++) f['makeChoice_ang' + i](); 

yeah I realized that after I read the other answers. The advantage here though (if its even an advantage), is you have names for the functions.

If I understand correctly what you're trying to do:

This will call the function created by that string concatenation. If i = 5 , then it would call makeChoice_ang5() .

In javascript, functions are treated as normal variables, just like a string or an int. obviously they have some extra features, but you can use them in the same way, for example, you could store a number of functions in an array, or pass a function to another function. Given that, I can't see any need to name functions in the way it looks like you're trying to.

I wish I could give you some more help for your specific problem, but it's a little hard to understand, sorry.

You could try changing your unCheckRadio function so that it takes a function as a parameter:

function unCheckRadio(num, func)

and then you'd call it like this:

function unCheckRadio(5, function() < // do whatever here. >); 

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How to Pass Numbers as Arguments in JavaScript Functions: A Comprehensive Guide

Learn how to pass numbers in function on js with this comprehensive guide. Understand pass by value, passing an unknown number of arguments, converting strings to integers, using destructuring assignment, and passing arrays as function arguments.

If you’re just starting out with JavaScript, you might be wondering how to pass numbers as arguments in JavaScript functions. In this article, we’ll cover everything you need to know about passing numbers as arguments in JavaScript functions, including pass by value, passing an unknown number of arguments , converting strings to integers, destructuring assignment, and passing arrays as function arguments .

JavaScript Functions and Arguments

Before we dive into the specifics of passing numbers as arguments in JavaScript functions, let’s start with a quick overview of JavaScript functions and arguments. In JavaScript, a function is a block of code that performs a specific task. You can define a function using the function keyword, followed by the function name, and a set of parentheses that contain the function’s parameters. For example:

In this example, multiply is the function name, and a and b are the parameters. When you call a function, you can pass arguments to the function by including them in the parentheses. For example:

In this example, 2 and 3 are the arguments that are passed to the multiply function.

Passing Numbers as Arguments in JavaScript Functions

Now that we understand the basics of JavaScript functions and arguments, let’s dive into passing numbers as arguments in JavaScript functions.

Understanding Pass by Value

In JavaScript, all function arguments are passed by value. This means that when you pass a variable to a function, a copy of the variable’s value is created and passed to the function, rather than a reference to the variable itself. For example:

let x = 2;function addOne(y) < y = y + 1; return y; >addOne(x); // returns 3 console.log(x); // still returns 2 

In this example, x is a variable that is equal to 2 . When we call the addOne function and pass x as an argument, a copy of the value of x (which is 2 ) is created and passed to the function as the variable y . Inside the function, y is incremented by 1 , and the result ( 3 ) is returned. However, when we log the value of x to the console, it still returns 2 , because the original value of x was not changed by the function.

To pass a number to a function, simply include it in the parentheses when calling the function. For example:

function multiplyByTwo(x) < return x * 2; >multiplyByTwo(3); // returns 6 

In this example, we define a function called multiplyByTwo that takes a parameter x . When we call the function and pass 3 as an argument, the function returns 6 , because 3 * 2 = 6 .

Passing an Unknown Number of Arguments

Sometimes, you might not know how many arguments you need to pass to a function ahead of time. In JavaScript, you can pass any number of arguments to a function, regardless of what the function declaration specifies. One way to do this is using the arguments object or an array.

The arguments object is an array-like object that contains the passed arguments. You can access the arguments using the [] notation. For example:

function sum() < let total = 0; for (let i = 0; i < arguments.length; i++) < total += arguments[i]; >return total; >sum(1, 2, 3, 4, 5); // returns 15 

In this example, we define a function called sum that doesn’t take any parameters. Inside the function, we create a variable called total that is equal to 0 . We then loop through the arguments object and add each element to total . Finally, we return total . When we call the sum function and pass 1, 2, 3, 4, 5 as arguments, the function returns 15 , because 1 + 2 + 3 + 4 + 5 = 15 .

Another way to pass an unknown number of arguments is using an array. You can pass an array as an argument to a function, and then use the spread operator ( . ) to turn the array into a list of arguments. For example:

function multiplyAll(. args) < let total = 1; for (let i = 0; i < args.length; i++) < total *= args[i]; >return total; >multiplyAll(1, 2, 3, 4, 5); // returns 120 

In this example, we define a function called multiplyAll that takes any number of arguments using the spread operator ( . args ). Inside the function, we create a variable called total that is equal to 1 . We then loop through the args array and multiply each element by total . Finally, we return total . When we call the multiplyAll function and pass 1, 2, 3, 4, 5 as arguments, the function returns 120 , because 1 * 2 * 3 * 4 * 5 = 120 .

Converting Strings to Integers using parseInt()

Sometimes, you might need to convert a string to an integer before passing it as an argument to a function. JavaScript provides a built-in method called parseInt() that can be used to parse a value as a string and return the first integer. For example:

parseInt("123"); // returns 123 parseInt("4.56"); // returns 4 parseInt("Hello"); // returns NaN 

In this example, we use the parseInt() method to convert the strings "123" , "4.56" , and "Hello" to integers. The first two examples return the expected result, but the third example returns NaN (Not a Number), because "Hello" cannot be converted to an integer.

The Number() method can also be used to convert a value to a number. If the value cannot be converted, NaN is returned. For example:

Number("123"); // returns 123 Number("4.56"); // returns 4.56 Number("Hello"); // returns NaN 

In this example, we use the Number() method to convert the same strings to numbers. The first two examples return the expected result, but the third example returns NaN , because "Hello" cannot be converted to a number.

Destructuring Assignment

Destructuring assignment syntax allows you to unpack values from arrays or properties from objects, and assign them to variables. You can use destructuring assignment to pass multiple arguments to a function , without having to pass them individually. For example:

function printInfo(< name, age >) < console.log(`My name is $, and I am $ years old.`); >const person = < name: "John", age: 30, >;printInfo(person); // logs "My name is John, and I am 30 years old." 

In this example, we define a function called printInfo that takes an object with properties name and age . Inside the function, we use template literals to log a message to the console. We then create an object called person with properties name and age . Finally, we call the printInfo function and pass the person object as an argument. The function logs "My name is John, and I am 30 years old." to the console.

Passing Arrays as Function Arguments

JavaScript functions can accept an array as an argument. You can use the spread operator ( . ) to turn an array into a list of arguments. For example:

function sum(a, b, c) < return a + b + c; >const numbers = [1, 2, 3];sum(. numbers); // returns 6 

In this example, we define a function called sum that takes three parameters a , b , and c . We then create an array called numbers with the values [1, 2, 3] . Finally, we call the sum function and use the spread operator to pass the numbers array as arguments. The function returns 6 , because 1 + 2 + 3 = 6 .

The arguments object is also an array-like object that is accessible inside functions, and contains the passed arguments. For example:

function multiplyByTwo() < let total = 1; for (let i = 0; i < arguments.length; i++) < total *= arguments[i]; >return total; >multiplyByTwo(1, 2, 3, 4, 5); // returns 120 

In this example, we define a function called multiplyByTwo that doesn’t take any parameters. Inside the function, we create a variable called total that is equal to 1 . We then loop through the arguments object and multiply each element by total . Finally, we return total . When we call the multiplyByTwo function and pass 1, 2, 3, 4, 5 as arguments, the function returns 120 , because 1 * 2 * 3 * 4 * 5 = 120 .

How to write a function that accepts any number of

source code here https://github.com/jayanthbabu123/function-that-accepts-any-number-of Duration: 3:10

Other quick examples for passing numbers in JavaScript functions

In Javascript , in particular, variable arguments js code example

function foo() < for (var i = 0; i < arguments.length; i++) < console.log(arguments[i]); >>foo(1,2,3); //1 //2 //3

In Javascript , for example, javascript pass by value code example

function func(obj) < obj = JSON.parse(JSON.stringify(obj)); //If too slow, replace with other method of deep cloning obj.a += 10; return obj.a; >var myObj = ; func(myObj); //Returns 15 and myObj.a is still 5

Conclusion

Passing numbers as arguments in JavaScript functions is easy and straightforward. By understanding pass by value and using techniques like passing an unknown number of arguments, converting strings to integers, using destructuring assignment, and passing arrays as function arguments, you can create more efficient and effective JavaScript functions. By following best practices for javascript development and understanding common issues, you can improve your JavaScript coding skills and create more successful projects.

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