Help me optimize a regular expression
Help me optimize a regular expression
<form id='myForm'>
Enter phone number:<input type="text" id='idMyText' name="myText" onKeyUp="alphaToNum(this.value)">
</form>
<script>
// on each keypress in input box, I want to capture key pressed,
// determine if key pressed belong to group of identified characters
// if, so then convert to specified numeric equivalent and开发者_开发技巧 return character
// to text box.
// This mapping corresponds to numeric characters on blackberry device.
// Normally user has to press alt+letter to get numbers. This will provide
// quicker access to numeric characters on for numeric fields
function alphaToNum(e) {
x = e;
x = (x.replace(/W/, "1"));
x = (x.replace(/w/, "1"));
x = (x.replace(/E/, "2"));
x = (x.replace(/e/, "2"));
x = (x.replace(/R/, "3"));
x = (x.replace(/S/, "4"));
x = (x.replace(/D/, "5"));
x = (x.replace(/F/, "6"));
x = (x.replace(/Z/, "7"));
x = (x.replace(/X/, "8"));
x = (x.replace(/C/, "9"));
document.getElementById('idMyText').value = x;
}
</script>
You could use the /i
modifier so /W/i
will match both w
and W
(etc.). But all in all this looks more like a job for a translation table - you're only substituting single letters, so regular expressions are a bit overkill for this.
This worked for me... answered in another thread.. thanks!
<form id='myForm'>
Enter phone number:<input type="text" id='idMyText' name="myText" onKeyUp="alphaToNum(this.value)">
</form>
<script>
var conversionMap = {W:1,E:2,R:3,S:4,D:5,F:6,Z:7,X:8,C:9,
w:1,e:2,r:3,s:4,d:5,f:6,z:7,x:8,c:9};
function alphaToNum(){
var field = document.getElementById('idMyText');
var value = field.value;
var chr = value[value.length-1];
if(conversionMap[chr]) {
field.value = value.substr(0,value.length-1) + conversionMap[chr];
}
// prevent memory leak.
field = null;
}
</script>
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