Javascript Intercept string Several functional usage detailed

There are many ways to intercept a string (excluding the split () method that intercepts a number of groups based on incoming parameters) here is a substring, so do not say the split () method.

Slice (), substr (), substring () altogether three methods, each of which is different, they can pass one or two parameters, the first parameter is the starting position, slice () and substring () The second parameter is the ending position (the output to the previous character at the end position), and the substr is the character length, but the case is different when the negative numbers are passed in.

Here are some examples of negative numbers:

The code is as follows	Copy Code
var stringvalue = "Hello World"; Console.log (Stringvalue.slice (-3)); Console.log (Stringvalue.substring (-3)); Console.log (Stringvalue.substr (-3)); Console.log (Stringvalue.slice (3,-4)); Console.log (Stringvalue.substring (-4, 3)); Console.log (Stringvalue.substring (3,-4)); Console.log (STRINGVALUE.SUBSTR (3,-4)); Output: Rld Hello World Rld Lo W Hel Hel

The last one is an empty string, and the substring bar is converted to 0, which seems to mean from 0 to another parameter. Slice () The mean minus sign is the reverse number.

Add: Using regular expressions
Method 2

The code is as follows	Copy Code
<script> Alert ("ABCDEFG". Match (/.*) (. { 2})/) [1]) </script> <script> Alert ("ABCDEFG". Match (/.{ 2}$/)) </script>

And like IndexOf, you can.

The following example illustrates the use of the IndexOf method.

code is as follows	copy code
function Indexdemo (str2) { var str1 = ' Babebibobubabebibobu ' var s = str1.indexof (STR2); return (s); }