Java; String replace (school project)?

Advanced replacements with Regex

Complex pattern matching with Flag settings

The Pattern class allows for advanced pattern matching and additional flags like DOTALL and CASE_INSENSITIVE. Here's how it's done:

// Mission: To boldly match what no one has matched before
Pattern pattern = Pattern.compile("x\\^([0-9]+)", Pattern.CASE_INSENSITIVE);
Matcher matcher = pattern.matcher("X^3 + x^5");
String result = matcher.replaceAll("<sup>$1</sup>");
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Sanitize your strings, save your app

Remember to sanitize input and escape HTML characters for preventing script injections and ensuring safety. Use HTML entities like < for < and > for >.

// Nice try, XSS isn't welcome here
String userContent = "<script>naughty()</script>";
String safeContent = userContent.replaceAll("\\<.*?>", "");
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Robust Error Handling

In the realm of regex, errors could happen. However, a try-catch block can catch these.

// Catch 'em all! Nope, not Pokémon, but exceptions!
try {
    String secureText = someInput.replaceAll("\\<.*?>", "");
} catch (PatternSyntaxException ex) {
    // Handle exception here
}
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Nuances of String Replacement

String replacement might not be a direct one-for-all task as unintended alterations could occur. When applying multiple replacements, a little process planning won't hurt.

// It's like disarming a bomb. One wrong cut, and boom!
String complexString = "Use x^2, x^3, and x^4 in equations";
// Perform replacements separately, considering dependencies among them
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Regex for Pretty Formatting

You've got a polynomial string to work around with that needs HTML formatting for better readability. Let's drum up that solution!

Dynamic Formatting with replaceAll()

If x^2 + y^2 is the regular scene, we should see x<sup>2</sup> + y<sup>2</sup> for the finale. Here's where replaceAll() comes on stage:

// Lights, Camera, Action!
String polynomial = "3x^2 + 4y^2";
String formatted = polynomial.replaceAll("\\^([0-9]+)", "<sup>$1</sup>");
// Curtain drop: "3x<sup>2</sup> + 4y<sup>2</sup>"
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Backreferences — Visibility Cloak

Using backreferences in regex patterns (like $1) unveils the captured groups, allowing us to do substitutions precisely without goofing up any unplanned parts of the string.

Precision through Testing

You don't want your strings to go haywire, do you? Thus, thorough testing with a variety of inputs will make your string replacements failsafe.

Regex — The Swiss Army Knife for Strings

Regex can be the Swiss Army knife for your textual challenges; validating, searching, and transforming texts are tasks you'll ace.

• Defending your kingdom against invalid emails and phone numbers? Regex has your back!
• A treasure hunt for patterns? Regex sets the grid!
• Midas touch to transform text, say, markdown to HTML? Regex is the spell you need!