Chinese New Year has been relatively busy, let everyone down.
Learn the function today, although the statement has not finished.
Functions are a very important part of the JavaScript language, but they are also complex.
Here's a look at JavaScript functions.
functions are function plus function names and a pair with parameter brackets, and curly braces, where the braces are
The principal JavaScript statement.
Cases:
function Hanshuname (JS)//hanshuname is the name of the function.
{
document.write (JS, "<br>"); is the principal statement of the function.
}
Functions can be nested as follows:
function Qiantao (a,b) {
function Lqiantao (x) {return x*x}
Return Math.sqrt (Lqiantao (a) +lqiantao (b));
}
Functions can also be applied as data, so functions such as assignment, storage, delivery, and so on, can be handled like other data.
Cases:
function Zhi (x) {return x*x}
In fact, the function name has no meaning, but only the variable name that holds the function.
A=zhi (6);//a Store is the number 36;
b=zhi;//now B and Zhi refer to the same function.
C=b (5);//c Store is the number 25.
In a function body, an identifier arguments always has a special meaning, which is a special property of the calling object that refers to the actual parameter object. This actual parameter object has a large number of useful properties. In addition, it also has the role of an array.
Although a JavaScript function is defined with a fixed parameter, the number of arguments passed to it can be arbitrary when the function is invoked, and the array arguments[] allows full access to those actual parameter values. In addition, arguments has a length attribute, see the following example:
function Zhi (x,y,z)
{
if (Arguments.length!=3) {
Alert ("function Zhi called with" +arguments.length+ "Arguments,but it expects 3 arguments.");
return null;
}
}
Array arguments[] Also developed an important possibility for JavaScript functions to write functions that can accept any number of actual parameters.
function Zhi ()
{
var m=number.negative_infinity;
Traverse all Parameters
Retrieves and remembers the largest one.
for (Var i=0;i<arguments.length;i++)
if (arguments>m) m=arguments;
Returns the maximum parameter value.
return m;
}
var Lazgest=zhi (1,10,100,2,3,1000,4,5,10000,6);
You can also use the arguments[] array to write a function.
Calling the JS function
<a href= "#" onclick= "functionname ()" >link text</a>
<a href= "Javascript:functionname ()" >link text</a>
Let's talk about this today, the next section continues to say function.
