65 lines
3.4 KiB
Markdown
65 lines
3.4 KiB
Markdown
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Built-in String Functions
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========================
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{{#include ../links.md}}
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The following standard methods (mostly defined in the [`MoreStringPackage`](/rust/packages.md) but excluded if
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using a [raw `Engine`]) operate on [strings]:
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| Function | Parameter(s) | Description |
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| ------------------------- | ------------------------------------------------------------ | ------------------------------------------------------------------------------------------------- |
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| `len` method and property | _none_ | returns the number of characters (not number of bytes) in the string |
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| `pad` | character to pad, target length | pads the string with an character to at least a specified length |
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| `+=` operator, `append` | character/string to append | Adds a character or a string to the end of another string |
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| `clear` | _none_ | empties the string |
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| `truncate` | target length | cuts off the string at exactly a specified number of characters |
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| `contains` | character/sub-string to search for | checks if a certain character or sub-string occurs in the string |
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| `index_of` | character/sub-string to search for, start index _(optional)_ | returns the index that a certain character or sub-string occurs in the string, or -1 if not found |
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| `sub_string` | start index, length _(optional)_ | extracts a sub-string (to the end of the string if length is not specified) |
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| `crop` | start index, length _(optional)_ | retains only a portion of the string (to the end of the string if length is not specified) |
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| `replace` | target character/sub-string, replacement character/string | replaces a sub-string with another |
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| `trim` | _none_ | trims the string of whitespace at the beginning and end |
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Examples
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--------
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```rust
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let full_name == " Bob C. Davis ";
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full_name.len == 14;
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full_name.trim();
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full_name.len == 12;
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full_name == "Bob C. Davis";
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full_name.pad(15, '$');
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full_name.len == 15;
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full_name == "Bob C. Davis$$$";
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let n = full_name.index_of('$');
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n == 12;
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full_name.index_of("$$", n + 1) == 13;
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full_name.sub_string(n, 3) == "$$$";
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full_name.truncate(6);
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full_name.len == 6;
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full_name == "Bob C.";
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full_name.replace("Bob", "John");
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full_name.len == 7;
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full_name == "John C.";
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full_name.contains('C') == true;
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full_name.contains("John") == true;
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full_name.crop(5);
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full_name == "C.";
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full_name.crop(0, 1);
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full_name == "C";
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full_name.clear();
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full_name.len == 0;
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```
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