An easy and fast in-memory string builder for Node.js.
const StringBuilder = require("node-stringbuilder"); const sb = new StringBuilder("Hi"); sb.appendLine(",").append("This is a simple example demonstrating how to use this module."); console.log(sb.toString()); // Hi, // This is a simple example demonstrating how to use this module. sb.insert("Text can be added into any position of this builder."); sb.replace(53, 118, "Or replace the existing text."); console.log(sb.toString()); // Text can be added into any position of this builder.HOr replace the existing text. sb.deleteCharAt(52).insert(52, " "); console.log(sb.toString()); // Text can be added into any position of this builder. Or replace the existing text. sb.toLowerCase().replaceAll("text", "string"); console.log(sb.toString()); // string can be added into any position of this builder. or replace the existing string. console.log(sb.clone().reverse().toString()); // .gnirts gnitsixe eht ecalper ro .redliub siht fo noitisop yna otni dedda eb nac gnirts console.log(sb.toString(0, 19)); // string can be added console.log(sb.length()); // 86 console.log(sb.count()); // 15 console.log(sb.indexOf("is")); // Uint32Array [ 43, 72 ] console.log(sb.indexOfSkip("is")); // Uint32Array [ 43, 72 ] console.log(sb.lastIndexOf("is")); // Uint32Array [ 72, 43 ] console.log(sb.indexOfRegExp(/is/g)); // { index: [ 43, 72 ], lastIndex: [ 45, 74 ] } console.log(sb.repeat().indexOf("is")); // Uint32Array [ 43, 72, 129, 158 ] sb.substring(11, 37); console.log(sb.toString()); // be added into any position console.log(sb.equalsIgnoreCase("be Added into Any position")); // true console.log(sb.toBuffer()); // UTF-8 encoded- Implemented with N-API.
- Operating strings in a scalable buffer.
- Multiple types of data are allowed to input.
- Strings
- Buffers(UTF-8 encoded)
- Instances of this
StringBuildermodule - ReadStream(to read file)
- Numbers, booleans, other objects
- Fast string search algorithm(Boyer-Moore-MagicLen)
- Clonable
Import this module by using require function.
const StringBuilder = require('node-stringbuilder');Use new operator or from function to create a StringBuilder instance.
const sb1 = new StringBuilder(); // or const sb2 = StringBuilder.from();When creating an instance of StringBuilder, you can initialize the text and capacity.
const sb = StringBuilder.from("First", 4096);By default, a block of buffer space used by StringBuilder is 128 characters. The space of the buffer can be expanded or shrinked by blocks.
// To expand const newCapacity = 65536; sb.expandCapacity(newCapacity); // To shrink sb.shrinkCapacity();If some text are added into StringBuilder, StringBuilder will check its space. And if the space is too small, it will re-alloc a bigger one automatically. This re-allocation has overheads, if it does this frequently, your program may be slowed down. Therefore, if you can predict the length of your text, please set the capacity when creating a StringBuilder instance.
Concat text.
sb.append("string").append(123).append(false).append(fs.createReadStream(path));Add a new line after append.
sb.appendLine("string");Append text repeatedly.
sb.appendRepeat("string", 3);Append a file asynchronizely.
await sb.appendReadStream(fs.createReadStream(path));Insert text to any position.
sb.insert("string"); // To the head. sb.insert(5, "string");Replace text to the position in a range of index.
sb.replace(4, 15, "string");Replace existing substrings to another.
sb.replacePattern("old", "new"); sb.replacePattern( "old", "new", offset, limit );Replace all existing substrings to another.
sb.replaceAll("old", "new");Delete text from a range of index.
sb.delete(4, 15);Delete a character at a index.
sb.deleteCharAt(4);Clear all text, but preserve the capacity.
sb.clear();Reserve text in a range of index.
sb.substring(1, 5); // input the start and end indexsb.substr(1, 5); // input the start index and lengthReverse text.
sb.reverse();Convert text to upper or lower case.
sb.upperCase(); sb.lowerCase();Remove any leading and trailing whitespace.
sb.trim();Repeat current text for specific count.
sb.repeat(1);Expand the capacity of this StringBuilder.
sb.expandCapacity(4096).append("string");Expand and get the updated capacity,
const capacity = sb.expandCapacity(4096, true);Shrink the capacity of this StringBuilder.
sb.shrinkCapacity().clone().append("string");Shrink and get the updated capacity,
const capacity = sb.shrinkCapacity(true);To get the length of this StringBuilder,
const length = sb.length();To get the length of this StringBuilder,
const capacity = sb.capacity();To count the words,
const words = sb.count();Build a string of a specific range of index.
const str = sb.toString(4, 10);Build a UTF-8 buffer of a specific range of index.
const buffer = sb.toBuffer(4, 10);To get the full text,
const text = sb.toString(); const buffer = sb.toBuffer();To get one character at a specific index,
const c = sb.charAt(4);Search substrings from the head,
const indexArray = sb.indexOf("string"); const indexArray2 = sb.indexOf("string", offset, limit);Search substrings from the head by using RegExp,
var indexArray = sb.indexOf(/string/g);Search substrings from the end,
const indexArray = sb.lastIndexOf("string");Determine whether the two strings are the same.
const equal = sb.equals("string");To ignore the case of letters,
const equal = sb.equalsIgnoreCase("string");Determine whether it starts or ends with a specific pattern.
const start = sb.startsWith("string"); const end = sb.endsWith("string");RegExp is not supported in startsWith and endsWith methods.
Clone this StringBuilder.
const newSB = sb.clone();To run the test suite, first install the dependencies, then run npm test:
npm install npm testTo run the benchmark suite, first install the dependencies, then run npm run benchmark:
npm install npm run benchmarkHere is my result,
Append - 43 milliseconds ✓ Natively append text 1000000 times (43ms) - 567 milliseconds ✓ Use StringBuilder to append text 1000000 times (567ms) - 1278 milliseconds ✓ Use StringBuilder to insert text 1000000 times at the end (1287ms) - 17 milliseconds ✓ Use StringBuilder to append text 1000000 times repeatly Insert - 92 milliseconds ✓ Natively insert text 10000 times (92ms) - 10 milliseconds ✓ Use StringBuilder to insert text 10000 times Delete - 1427 milliseconds ✓ Natively delete text 5000 times (1429ms) - 87 milliseconds ✓ Use StringBuilder to delete text 5000 times (88ms) Replace - 1511 milliseconds ✓ Natively replace text 5000 times (1513ms) - 85 milliseconds ✓ Use StringBuilder to replace text 5000 times (86ms) Replace Pattern - 37 milliseconds ✓ Natively replace text with the same length by using a RegExp pattern - 20 milliseconds ✓ Use StringBuilder to replace text with the same length by using a pattern - 35 milliseconds ✓ Natively replace text by using a RegExp pattern - 29 milliseconds ✓ Use StringBuilder to replace text by using a pattern Equals - 2 milliseconds ✓ Natively check the equal 50000 times - 13 milliseconds ✓ Use StringBuilder to check the equal 50000 times EqualsIgnoreCase - 21 milliseconds ✓ Natively check the equal 50000 times - 19 milliseconds ✓ Use StringBuilder to check the equal 50000 times IndexOf - 65 milliseconds ✓ Natively search text (65ms) - 2 milliseconds ✓ Use StringBuilder to search text Reverse - 516 milliseconds ✓ Natively reverse text (516ms) - 14 milliseconds ✓ Use StringBuilder to reverse textAccording to the result of benchmark, if you just want to append a few different strings, please append them by using native operator + instead of this module.