Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
121 views
in Technique[技术] by (71.8m points)

How to determine if Javascript array contains an object with an attribute that equals a given value?

I have an array like

vendors = [{
    Name: 'Magenic',
    ID: 'ABC'
  },
  {
    Name: 'Microsoft',
    ID: 'DEF'
  } // and so on... 
];

How do I check this array to see if "Magenic" exists? I don't want to loop, unless I have to. I'm working with potentially a couple thousand records.

question from:https://stackoverflow.com/questions/65831241/check-if-particular-key-value-pair-exists-in-javascript-array-or-not

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

2018 edit: This answer is from 2011, before browsers had widely supported array filtering methods and arrow functions. Have a look at CAFxX's answer.

There is no "magic" way to check for something in an array without a loop. Even if you use some function, the function itself will use a loop. What you can do is break out of the loop as soon as you find what you're looking for to minimize computational time.

var found = false;
for(var i = 0; i < vendors.length; i++) {
    if (vendors[i].Name == 'Magenic') {
        found = true;
        break;
    }
}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...