Reading a Portion of a String : String « Language Basics « JavaScript DHTML

Reading a Portion of a String

<TITLE>String Slicing and Dicing, Part II</TITLE>
var mainString = "This is a test"

function showResults() {
    var form = document.forms[0]
    var param1 = parseInt(form.param1.options[form.param1.selectedIndex].value)
    var param2 = parseInt(form.param2.options[form.param2.selectedIndex].value)

    if (!param2) {
    } else {
        alert(mainString.substr(param1, param2));
<BODY onLoad="showResults()">
<B>String substr() Method</B>Text used for the methods:<B>This is a test<BR>
<TR><TH>String Method</TH><TH>Method Parameters</TH></TR>
<TD>string.substr()</TD><TD ROWSPAN=3 VALIGN=middle>
(&nbsp;<SELECT NAME="param1" onChange="showResults()">
<SELECT NAME="param2" onChange="showResults()">
    <OPTION >(None)
    <OPTION VALUE=10>10
    <OPTION VALUE=20>20
</SELECT>&nbsp;) </TD>


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