Javascript- How to store string by searching for first couple letters

Question

I have a question on how to store a string in Javascript when you only know the first couple letters. Here is an example. The HTML code is this:

<HTML>

<HEAD>
    <TITLE>Your Title Here</TITLE>
</HEAD>

<BODY BGCOLOR="FFFFFF">
    <CENTER>
        <IMG SRC="clouds.jpg" ALIGN="BOTTOM"> </CENTER>
    <HR>
    <a href="http://somegreatsite.com">Link Name</a> is a link to another nifty site
    <H1>This is a Header</H1>
    <H2>This is a Medium Header</H2> Send me mail at <a href="mailto:support@yourcompany.com">
support@yourcompany.com</a>.
    <P> This is a new paragraph!
        <A href="/003U0000015Rmza">Persons's Name/A> </P>
<P> <B>This is a new paragraph!</B> </P>
<BR> <B><I>This is a new sentence without a paragraph break, in bold italics.</I></B>
<HR>
</BODY>
</HTML>

I need to store the full string of '003U0000015Rmza', but I will only know that it starts with '003'.

Is there a way in Javascript to search for the characters '003', and once it's found, store the full string in a variable?

Thanks in advance!

Can you change the HTML? is the value always in an ``? If so, always preceded with `/` ? — Alex K., Oct 17 '14 at 16:32

score 0 · Answer 1 · edited May 23 '17 at 10:33

0

You want to have a way to see if a string starts with a certain pattern. One easy way is to overload the String type to have a startsWith() function .

Look at this example.

edited May 23 '17 at 10:33

Community

1
1

answered Oct 17 '14 at 16:35

Gui Rava

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4
6

score 0 · Answer 2 · answered Oct 17 '14 at 21:02

This is where String.indexOf() can come in handy.

inThis.indexOf(findThat) function searches the string it's called on for the string you pass in. It returns a number stating where to find the string you looked for (findThat) within the string that you looked in (inThis). If it doesn't find the string at all, it returns -1, which isn't a valid position in any string.

To use this to find whether inThat starts with findThis, you can do something like this:

if (inThis.indexOf(findThat) === 0) {
    // do something
}

To store that string somewhere, you might try this:

var myString; // The place where we'll store the string
if (theLink.href.indexOf('003') === 0) {
    // This is the string we need to store
    myString = theLink.href;
}

This works because the first character in any string is at position 0. So if indexOf found '003' at position 0, then we know the string starts with '003'.

Javascript- How to store string by searching for first couple letters

2 Answers2