extractSegmentByIndex — GTM Variable Template for URL

VARIABLES › URL

extractSegmentByIndex CORE URL

Direct (.tpl) Apply (.tpl)

Extracts a URL path segment by its index position.

---

When to Use This

URL Processing

Parse, build, decode, and manipulate URLs and query parameters.

Extraction

Pull specific values, segments, or patterns from complex data structures.

---

Examples

Extract first segment▶ Try

INPUT

Pathname: /products/shoes/nike
Segment Index: 0
Remove Trailing Slash: false
Remove Empty Segments: false
Default Value (optional): undefined

OUTPUT

""

Extract middle segment▶ Try

INPUT

Pathname: /products/shoes/nike
Segment Index: 2
Remove Trailing Slash: false
Remove Empty Segments: false
Default Value (optional): undefined

OUTPUT

shoes

---

GTM Configuration

This is what you'll see when you open this variable in Google Tag Manager. Hover the icons for details.

extractSegmentByIndex

Read-Only Try Live

Pathname

💾 The pathname string to extract segment from (e.g., "/products/shoes/nike").

Supported formats:
  ✓ String: path with forward slashes

Segment Index

💾 The zero-based index of the segment to extract. Index 0 is the root (""), index 1 is the first segment after root.

Supported formats:
  ✓ Number: 0, 1, 2, etc.

Remove Trailing Slash

☑️ If enabled, removes trailing slash from pathname before splitting (e.g., "/products/" becomes "/products").

Remove Empty Segments

☑️ If enabled, removes empty segments from the path (except the leading empty string representing root).

Default Value (optional)

💾 The value to return if the index is out of range or the input is invalid.

Supported formats:
  ✓ Any type

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the pathname before extracting segments (e.g., normalize URL, decode URI components).

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the extracted segment before returning it (e.g., str => str.toUpperCase(), str => decodeURIComponent(str)). Useful for chaining transformations on the output.

Pathname string

💡 Type any text to see the result update live

🎯 Using special value — click input to type instead

Test with:

Falsy undefined null "" empty 0 false NaN

Truthy true 42 "hello" {} empty [] empty {a:1} [1,2,3]

Segment Index number

Remove Trailing Slash

Remove Empty Segments

Default Value (optional) string

🔗 Result Handling — Chain Variables

Chain apply-mode variables to the output. Each variable receives the result of the previous one.

extractSegmentByIndex()

+ Chain another variable

---

Related Variables

Same category: URL

→ buildUrlFromParts → completeUrl → decodeUri → decodeUriComponent → encodeURIComponent → encodeUri → extractHash → extractHashParams → extractHost → extractHostname → extractOrigin → extractPasword → extractPathname → extractPort → extractProtocol → extractSearch → extractSearchParams → extractUserName → hasFragment → hasParameterWithValue → hasQueryString → parseUrlComponents → stringToPath

---

Under the Hood

📜 View Implementation Code

/**
 * Returns a specific segment from a pathname string using its index.
 *
 * @param {string} data.src - The pathname string to extract from (e.g., "/products/shoes").
 * @param {number} data.idx - The index of the segment to return (0-based).
 * @param {boolean} [data.rts=false] - Whether to remove a trailing slash before splitting.
 * @param {boolean} [data.rem=false] - Whether to remove empty segments (except the leading one).
 * @param {*} [data.def] - The default value to return if index is out of range or input is invalid.
 * @param {Function|string} [data.out] - Optional output handler: function to transform result or string with format.
 *
 * Direct-mode specific parameters:
 * @param {Function} [data.pre] - Optional pre-processor function to transform src before processing.
 * 
 * @returns {string|*} The path segment at the specified index, or the default value if not found.
 *
 * @framework ggLowCodeGTMKit
 */
const extractSegmentByIndex = function(pathname, index, removeTrailingSlash, removeEmpty, defaultValue) {
    if (typeof pathname !== "string" || typeof index !== "number") {
        return defaultValue;
    }
    
    let normalizedPath = pathname[0] === "/" ? pathname : "/" + pathname;
    
    if (removeTrailingSlash && normalizedPath[normalizedPath.length - 1] === "/") {
        normalizedPath = normalizedPath.slice(0, -1);
    }
    
    let segments = normalizedPath.split("/");
    
    if (removeEmpty) {
        segments = segments.filter(function(segment) { return segment.length > 0; });
        segments.unshift('');
    }
    
    return index >= 0 && index < segments.length ? segments[index] : defaultValue;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// extractSegmentByIndex - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(extractSegmentByIndex(value, data.idx, data.rts, data.rem, data.def));
// ===============================================================================
// extractSegmentByIndex(...) – Apply Mode
// ===============================================================================
/*
return function(pathname, index, removeTrailingSlash, removeEmpty, defaultValue) {
   index = data.rp1 ? data.idx : index;
   defaultValue = data.rp2 ? data.def : defaultValue;
   return out(extractSegmentByIndex(pathname, index, data.rts, data.rem, defaultValue));
};
*/

🧪 View Test Scenarios (10 tests)

✅ '[example] Extract first segment'
✅ '[example] Extract middle segment'
✅ Test with trailing slash removal
✅ Test with index out of range returns default
✅ Test with empty segment removal
✅ Test without leading slash (auto-added)
✅ Test with non-string input returns default
✅ Test with single segment path
✅ Test with root path only
✅ Test last segment extraction