javascript hash tutorial code example

Example 1: java script hash

function hashFnv32a(str, asString, seed) {
    /*jshint bitwise:false */
    var i, l,
        hval = (seed === undefined) ? 0x811c9dc5 : seed;

    for (i = 0, l = str.length; i < l; i++) {
        hval ^= str.charCodeAt(i);
        hval += (hval << 1) + (hval << 4) + (hval << 7) + (hval << 8) + (hval << 24);
    }
    if( asString ){
        // Convert to 8 digit hex string
        return ("0000000" + (hval >>> 0).toString(16)).substr(-8);
    }
    return hval >>> 0;
}

Example 2: js hash table example

var myHash = new Hash('one',[1,10,5],'two', [2], 'three',[3,30,300]);

Example 3: js hash table example

// Simple ECMA5 hash table
Hash = function(oSource){
  for(sKey in oSource) if(Object.prototype.hasOwnProperty.call(oSource, sKey)) this[sKey] = oSource[sKey];
};
Hash.prototype = Object.create(null);

var oHash = new Hash({foo: 'bar'});
oHash.foo === 'bar'; // true
oHash['foo'] === 'bar'; // true
oHash['meow'] = 'another prop'; // true
oHash.hasOwnProperty === undefined; // true
Object.keys(oHash); // ['foo', 'meow']
oHash instanceof Hash; // true

Example 4: How to use hash in javascript

var h = new Object(); // or just {}
h['one'] = 1;
h['two'] = 2;
h['three'] = 3;

// show the values stored
for (var k in h) {
    // use hasOwnProperty to filter out keys from the Object.prototype
    if (h.hasOwnProperty(k)) {
        alert('key is: ' + k + ', value is: ' + h[k]);
    }
}