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To parse strings in Javascript you need six functions:
substr, split, concat, replace, search, and slice
substr(StartExtraction, ExtractionLength)
-returns the requested string from StartExtraction through ExtractionLength
-StartExtraction is zero based (the index of the first character is 0)
-ExtractionLength is not zero based (if you pass in 5, the function will count 1-5)
-if StartExtraction is a negative number, the function will count
backwards starting from the end of the string and loop if necessary
(var1=abcdefg, StartExtraction=-2, it will start at e)
Example:
var1 = "abcdefghijk"
var2 = var1.substr(2, 3)
document.write("var2="+ var2 + "<br>")
Result:
var2=cde
split(Delimiter, MaxNumToSplit)
-takes a string and creates an array out of it
-the delimiter or separator is removed from the returned array
-if the delimiter is left out, the array returned will contain the entire
string in one element
Example:
var1 = "one, two, three, four"
var2 = var1.split(",")
document.write("var1=" + var1 + "<br>");
document.write("var2 has " + var2.length + " elements:<br>");
for (var i=0; i < var2.length; i++) {
document.write("Array Item #" + i + "=" + var2[i] + "<br>");
}
Result:
var1=one, two, three, four
var2 has 4 elements:
Array Item #0=one
Array Item #1= two
Array Item #2= three
Array Item #3= four
concat(StringToAdd)
-returns the combined two strings
Example:
var1 = "This house is "
var2 = "old and scary."
document.write("var1 = " + var1 + "<br>")
document.write("var2 = " + var2 + "<br>")
document.write("combined = " + var1.concat(var2) + "<br>")
Result:
var1 = This house is
var2 = old and scary.
combined = This house is old and scary.
replace(ReplaceThis, ReplaceWith)
-returns a new string with ReplaceThis replaced by ReplaceWith.
-this function does not change the string being operated on, it returns a
new one, therefore if you want to change the string being operated on you must set
that string equal to the change (see below example)
-if you want to replace globally include g in ReplaceThis
-if you want to ignore case include an i in ReplaceThis
-an example of this would be to set var2 = /*/gi;
Example:
var1 = "This*is*my*story!"
var2 = "*"
document.write("BEFORE var1=" + var1 + "<br>");
var1 = var1.replace(var2, " ")
document.write("AFTER var1=" + var1 + "<br>");
Result:
BEFORE var1=This*is*my*story!
AFTER var1=This is*my*story!
search(FindThis)
-returns the index (or location) where the string was found
-if FindThis is not found the function will return -1
Example:
var1 = "abcdefg"
var2 = "c"
if (var1.search(var2) > -1) {
document.write("var2 was found in var1");
} else document.write("var2 was not found in var1");
Result:
var2 was found in var1
slice(StartSlice, EndSlice)
-returns the requested string minus what was taken out
-both parameters have a zero based index
Example:
var1 = "abcdefghijk"
var2 = var1.slice(3, 8);
document.write("var2=" + var2 + "<br>")
Result:
var2=defgh
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