JavaScript Tutorial/String/String comparisons

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Compare two strings

<HTML>
<BODY>
<SCRIPT language="JavaScript">
<!--
var myVar="AA";

if(myVar=="AA") {
    window.alert("AA");
} else  {
    window.alert("Not AA");
}
//-->
</SCRIPT>
</BODY>
</HTML>


localeCompare

localeCompare() helps sort string values

localeCompare() method takes the string to compare to.

localeCompare() returns one of three values:

If the String object comes alphabetically before the string argument, a negative number is returned.

If the String object is equal to the string argument, 0 is returned.

If the String object comes alphabetically after the string argument, a positive number is returned.



var oStringObject = new String("yellow");
alert(oStringObject.localeCompare("brick"));     //outputs "1"
alert(oStringObject.localeCompare("yellow"));    //outputs "0"
alert(oStringObject.localeCompare ("zoo"));     //outputs "-1"


String comparisons

<html>
<head>
<title>String comparisons</title>
<script type="text/javascript" language="javascript">
<!-- //
onload = function(){
var firstString = new String("AAA");
var secondString = new String("aaA");
document.write("<h3>Direct comparison of the two strings</h3>");
var comparison = (firstString==secondString);
document.write(comparison);
}
// -->
</script>
</head>
<body>
</body>
</html>


String comparisons by converting strings to its uppercase form

<html>
<head>
<title>String comparisons</title>
<script type="text/javascript" language="javascript">
<!-- //
onload = function(){
    var firstString = new String("AAA");
    var secondString = new String("aaA");
    document.write("<h3>Comparison after conversion to upper case</h3>");
    var firstUpperString = firstString.toUpperCase();
    var secondUpperString = secondString.toUpperCase();
    document.write((firstUpperString==secondUpperString));
}
// -->
</script>
</head>
<body>
</body>
</html>


Use if statement with String.localeCompare

var oStringObject1 = new String("yellow");
var oStringObject2 = new String("brick");
var iResult = sTestString.localeCompare("brick");
if(iResult < 0) {
    alert(oStringObject1 + "comes before "+ oStringObject2);
} else if (iResult > 0) {
    alert(oStringObject1 + "comes after "+ oStringObject2);
} else {
    alert("The two strings are equal");
}