Fast and robust stringmap for JavaScript
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A fast and robust stringmap implementation that can hold any string keys, including __proto__, with minimal overhead compared to a plain object. Works in node and browsers.

The API is created to be as close to the ES6 Map API as possible. Prefer sm.remove("key") for deleting a key. ES6 Map uses map.delete("key") instead and for that reason sm['delete']("key") is available as a stringmap alias as well. Never do sm.delete("key") unless you're certain to be in the land of ES5 or later.


Available in examples.js

var StringMap = require("stringmap");

var sm1 = new StringMap();
sm1.set("greeting", "yoyoma");
sm1.set("check", true);
sm1.set("__proto__", -1);
console.log(sm1.has("greeting")); // true
console.log(sm1.get("__proto__")); // -1
console.log(sm1.keys()); // [ 'check', '__proto__' ]
console.log(sm1.values()); // [ true, -1 ]
console.log(sm1.items()); // [ [ 'check', true ], [ '__proto__', -1 ] ]
console.log(sm1.toString()); // {"check":true,"__proto__":-1}

var sm2 = new StringMap({
    one: 1,
    two: 2,
console.log(, key) {
    return value * value;
})); // [ 1, 4 ]
sm2.forEach(function(value, key) {
    // ...
console.log(sm2.isEmpty()); // false
console.log(sm2.size()); // 2

var sm3 = sm1.clone();
    a: {},
    b: [],
console.log(sm3.toString()); // {"check":true,"one":1,"two":2,"a":{},"b":[],"__proto__":-1}



Install using npm

npm install stringmap
var StringMap = require("stringmap");


Clone the repo and include it in a script tag

git clone
<script src="stringmap/stringmap.js"></script>