Find out if a Pine Script string is uppercase text

TL;DR
Build a StrIsUpper() helper so you can detect uppercase strings, highlight chart states, and trigger alerts when text changes.

At a Glance


Difficulty	Beginner
Time to implement	5-10 min
Category	Strings

Quick Actions

Quick Start

//@version=5
indicator("Uppercase check", overlay=false)

StrIsUpper(string source) =>
    sourceUpper = str.upper(source)
    sourceUpper != str.lower(source) and source == sourceUpper

text = input.string("NASDAQ", "Text to inspect")
isUpper = StrIsUpper(text)
plotchar(isUpper, "Uppercase?", "✅", location=location.top)

Why It Matters

Pine Script does not ship with a built-in uppercase detector. Comparing raw strings fails because "ABC" and "abc" are different even if you just want to know if the letters are capitalised. A helper that converts the input to both upper and lower case lets you answer questions like “Is the symbol description all caps?” or “Has my screener output changed format?”—useful for UI cues and alert conditions.

What You’ll Learn

Build a reusable StrIsUpper() utility
Test instrument metadata (ticker, description) for uppercase text
React to uppercase detection with backgrounds, labels, or alerts
Handle edge cases for numbers, symbols, and empty strings

Quick Reference

Call	Purpose
`str.upper(string)`	Returns an uppercase version of the string.
`str.lower(string)`	Returns a lowercase version of the string.
`StrIsUpper(string)`	Custom helper that checks if a string is uppercase text.
`bgcolor(color)`	Highlights the chart when uppercase text is detected.
`label.new(...)`	Displays the uppercase status directly on the chart.

Implementation Blueprint

Write the helper function
Convert the input to upper and lower case. Uppercase strings must differ from their lowercase version and match their uppercase version.
```
StrIsUpper(string source) =>
    uppercase = str.upper(source)
    uppercase != str.lower(source) and source == uppercase
```
Test the strings you care about
Apply the helper to literal strings, inputs, or instrument metadata.
```
symbolUpper = StrIsUpper(syminfo.ticker)
descUpper   = StrIsUpper(syminfo.description)
```

React to the result
Colour the background, raise alerts, or annotate the chart when uppercase text appears.

bgcolor(symbolUpper ? color.new(color.green, 80) : na)
if barstate.islast
    label.new(bar_index, high, "Description uppercase? " + str.tostring(descUpper))

Example Playbook

//@version=5
indicator("Uppercase watcher", overlay=true)

// 1. Helper function
StrIsUpper(string source) =>
    transformed = str.upper(source)
    transformed != str.lower(source) and source == transformed

// 2. Evaluate instrument metadata
descIsUpper = StrIsUpper(syminfo.description)
symbolIsUpper = StrIsUpper(syminfo.ticker)

// 3. React to uppercase descriptions
bgcolor(descIsUpper ? color.new(color.teal, 78) : na)

if barstate.islastconfirmedhistory
    txt = "Ticker uppercase: " + str.tostring(symbolIsUpper) +
        "\nDescription uppercase: " + str.tostring(descIsUpper)
    label.new(bar_index, high, txt, style=label.style_label_up, textcolor=color.white, bgcolor=color.new(color.blue, 65))

alertcondition(descIsUpper, "Description uppercase", "Instrument description switched to uppercase.")

Why this works.

Numbers or symbols alone return `false` because uppercase/lowercase versions match.
Strings with at least one letter that is not capitalised return `false` due to the equality check.
The helper function is pure and reusable—drop it into any script that needs uppercase detection.

Pro Tips & Pitfalls

Strip whitespace before testing if trailing spaces are possible (str.trim()).
Combine with str.replace() to filter out characters you want to ignore before checking.
Cache the helper in a separate include file if multiple scripts use it.
Remember that StrIsUpper("") returns false because there are no letters to validate.

Troubleshooting & FAQ

The function returns true for strings like “12345”

Use the double comparison (upper != lower) to ensure at least one alphabetical character exists. Without this clause numeric strings would incorrectly return true.

Can I reuse the helper for lowercase detection?

Yes—swap the comparisons so you test lower case against upper case or write a complementary StrIsLower() using the same pattern.

Key Takeaways

Pine Script lacks a built-in uppercase tester, so a lightweight helper fills the gap.
Comparing upper and lower transformations ensures the string has letters and they are capitalised.
Use the detection to power UI cues, alerts, or data validation workflows.
Handle edge cases (empty strings, numbers) to keep results predictable.

Keep Going

Open AI Editor to apply the pattern with guided assistance
Browse PineScript Examples for ready-to-run templates
Connect to Live Trading when you are ready to automate

Adapted from tradingcode.net, optimised for Algo Trade Analytics users.