JavaScript indexOf Startwith

Determine if a string starts with XX

1. Cut convert var str = "Ababaa", tags = Jquery.trim (str);

2. The IndexOf method runs!tags.indexof ("aba") = = True, which indicates that tags start with "abc", otherwise it does not start with "ABC".

3. Note that the IndexOf () method returns a positive number for -1,0,>0, while the JavaScript numbers object equals 0 o'clock can be converted to false, and the other values can only be converted to true;

The IndexOf () method returns the position of the first occurrence of a specified value in a string.

If the Boolean object has no initial value, or if the passed value is one of the following:

0,-0, NULL, "", false, undefined, NaN
The object it is set to false. For any and value it is set to true (even with the string "false")!

This method returns-1 if the value to search for never occurs.

JavaScript indexOf Startwith