Function substringBefore

substringBefore<T extends string | null = null>(
    s: Nullish,
    delimiter: string | RegExp,
    on_missing?: T,
): T
Returns the substring before the first occurrence of the delimiter.
Type Parameters
- T extends string | null = null
Parameters
- s: Nullish
  String (or null/undefined) to find the substring of.
- delimiter: string | RegExp
  Needle that marks where the cropped string should end.
- Optionalon_missing: T
  Value to return when s is nullish or delimiter is not found (defaults to null).
Returns T
- The substring that precedes the first occurrence of delimiter.
- on_missing if s is null/undefined or if the delimiter cannot be found.
Example
```
substringBefore("path/to/file.txt", '/');       // "path"
substringBefore("abc123xyz", /\d+/);            // "abc"
substringBefore(undefined, ':');                // null
substringBefore("no-needle", ':');              // null
substringBefore("no-needle", ':', 'default');   // 'default'
substringBefore(null, ':', '');                 // ''
```
- Defined in string/substring.ts:62
substringBefore<T extends string | null = null>(
    s: Nullable<string>,
    delimiter: string | RegExp,
    on_missing?: T,
): string | T
Returns the substring before the first occurrence of the delimiter.
Type Parameters
- T extends string | null = null
Parameters
- s: Nullable<string>
  String (or null/undefined) to find the substring of.
- delimiter: string | RegExp
  Needle that marks where the cropped string should end.
- Optionalon_missing: T
  Value to return when s is nullish or delimiter is not found (defaults to null).
Returns string | T
- The substring that precedes the first occurrence of delimiter.
- on_missing if s is null/undefined or if the delimiter cannot be found.
Example
```
substringBefore("path/to/file.txt", '/');       // "path"
substringBefore("abc123xyz", /\d+/);            // "abc"
substringBefore(undefined, ':');                // null
substringBefore("no-needle", ':');              // null
substringBefore("no-needle", ':', 'default');   // 'default'
substringBefore(null, ':', '');                 // ''
```
- Defined in string/substring.ts:63

Function substringBefore

Type Parameters

Parameters

Returns T

Example

Type Parameters

Parameters

Returns string | T

Example

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