JavaScript built-in top-level functions

Noun explanation :

1. built-in : ECMAscript

Built-in functions : ECMAscript 's own function number ()

Host function : BOM DOM alert () Prompt () confirm ();

Confirm () pops up a dialog box with a OK and cancel button to confirm that the return is true and that the return false is canceled.

2. Top Floor

String function: String . function ()

Array functions

A function of the top-level object that can act on any object.

Built-in top-level functions

1.escape () encodes a string

2.unescape () decodes the encoded string

3.Number () converted to numeric type

4.String () Convert to String type

5.Boolean () Convert to Boolean type

6.parseInt () converts a string to an integer type

7.parseFloat () converted to decimal

8.IsNaN() determines whether a number can be converted to a numeric type.

9.isFinite () determines whether a number is a poor number. Returns False if there are no poor numbers or numbers that cannot be converted to numeric types

10.eval () converts a string into a javascript command execution ( must conform to the JavaScript syntax specification, Otherwise, an error occurs ).

Ie:

Eval () takes effect in the current scope

Window.eval () takes effect in the current scope

ExecScript ()

Ff:

Eval () takes effect in the current scope

Window.eval () takes effect in the global

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JavaScript built-in top-level functions