JS: String.prototype.substr

By Xah Lee. Date: . Last updated: .

s.substr(index, length)

Return a substring of length length, starting at index

// substr example

const ss = "abcd";

console.log ( ss.substr(1,2) ); // bc

console.log ( ss.substr(1, 9) ); // bcd
// length longer than available, take to the end instead

Note: by ES2015 spec, the method substr is required only if the host is web browser. For example, not required in node.js.

Reference

ECMAScript 2015 §Annex B#sec-string.prototype.substr

JavaScript substring Topic

  1. JS: String.prototype.slice
  2. JS: String.prototype.substring
  3. JS: String.prototype.substr

JS String

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  11. String Object
  12. String.prototype
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