Introduction to two common methods of function calling in js _ javascript skills

This article mainly introduces two common methods for calling functions in js. If you need them, refer to the next js function.

Function test (aa) {window. alert ("You entered" + aa );}

Method 1: directly call

Test ("dddd ");

Method 2: assign a value to a variable

Var abc = test;

Abc ('China'); // call a function using variables

Note:

When we write this form, var abc = test ("dddd"); the function cannot be called through the abc variable.

In this way, when test has a return value, it will assign the return value to abc. When there is no return value, the value of abc is undefine.

In particular, JavaScript naturally supports variable parameters.

// Write a function that can accept any number and calculate their sum // It cannot be overloaded. The abc2 function name cannot be repeated function abc2 (n1) {// you can ignore the n1 parameter // There is an arguments in js that can access all input values. // Window. alert (arguments. length); // traverse all parameters for (var I = 0; I