Find an element in a JavaScript array
- by Aligned
Originally posted on: http://geekswithblogs.net/Aligned/archive/2014/08/22/find-an-element-in-a-javascript-array.aspxI needed a C# Dictionary like data structure in JavaScript and then a way to find that object by a key. I had forgotten how to do this, so did some searching and talked to a colleague and came up with this JsFiddle. See the code in my jsFiddle or below: var processingProgressTimeoutIds = [];
var file = {
name: 'test',
timeId: 1
};
var file2 = {
name: 'test2',
timeId: 2
};
var file3 = {
name: 'test3',
timeId: 3
};
processingProgressTimeoutIds.push({
name: file.name,
timerId: file.id
});
processingProgressTimeoutIds.push({
name: file2.name,
timerId: file2.id
});
processingProgressTimeoutIds.push({
name: file3.name,
timerId: file3.id
});
console.log(JSON.stringify(processingProgressTimeoutIds));
var keyName = 'test';
var match = processingProgressTimeoutIds.filter(function (item) {
return item.name === keyName;
})[0];
console.log(JSON.stringify(match));
// optimization
var match2 = processingProgressTimeoutIds.some(function (element, index, array) {
return element.name === keyName;
});
console.log(JSON.stringify(match2));
// if you have the full object
var match3 = processingProgressTimeoutIds.indexOf(file);
console.log(JSON.stringify(match3));
// http://jsperf.com/array-find-equal – from Dave
// indexOf is faster, but I need to find it by the key, so I can’t use it here
//ES6 will rock though, array comprehension! – also from Dave
// var ys = [x of xs if x == 3];
// var y = ys[0];
Here’s a good blog post on Array comprehension.
