Js-$.extend extension method makes method parameters more flexible_javascript skills

When doing JS development, we encapsulate complex third-party plug-ins and then expose a very simple method interface to the outside world. This is a commonly used method during development. In JS, our method parameters usually use JQ’s $.extend extension. Method to implement

Copy code The code is as follows:

function extend(arr) {
arr = $.extend({ name: 'zzl', sex: 'male', age: 31 }, arr || {});
alert("[Name:]" arr.name "[Sex:] " arr.sex "[Age:]" arr.age);
}

When the page is called:

Copy code The code is as follows:

extends< /a>The output content is:

That is, if we do not specify a value for arr, it will output the default value. What will happen if we assign a value to a certain attribute of the arr object?

Copy code The code is as follows:

extends

In the above code, we changed the nature of the name attribute, and the result output is :

That is, it only modifies the value of the specified attribute, and other values ​​of the object remain at their original default values.
The || operator in JS has the same function as the || , this function is similar to

in C#? ? operator, so || in JS is quite powerful, haha.