Front End Basics Review notes

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1. Delay Script: Add defer property, the script will be delayed until the entire page is resolved after the operation. The Defer property is used only for external script files.

<script type= "Text/javascript" defer= "defer" src= "Example.js" ></script>

2. Asynchronous script: Add Async property, only for external script files, similar to defer.

<script type= "Text/javascript" async= "async" src= "Example.js" ></script>

3. The value of the e notation equals the number in front of e multiplied by the exponential power of 10.

4.NaN is used to indicate a case in which an operand that would have returned a numeric value did not return a number

5. Numeric conversion: Number () parseint (), parsefloat () can receive two parameters, one for numeric value and one for several binary

String conversions: ToString (), which receives a parameter that is a binary

6.for-in statement:

for (var propname in window) {
      document.write (propname);
}

7.with statement: Set the scope of the code to a specific object

With (location) {
      var qs=search.substring (1);
      var hostname=hostname;
      var url=href;
}

8. Detection array, conversion method: toLocaleString (), toString (), valueof ()

9. Separator: Join () method (string);

Stack method: Push (), pop ();

Queue method: Push (), shift ();

Reordering: reverse ();