what is the best way to find string inside array in node.js?

Question

I have a node.js script where I want to find if a given string is included inside an array. how can I do this?

Thanks.

Blatant

I do not understand your question? You want to find a string inside an array? Please describe your question a little bit better. An commented example would be helpful. Some comments inside your fiddle would be also helpful to find out, what you want to know. – Puberulent

edit. please look again if you have time. – Blatant

Answer 1

If I understand correctly, you're looking for a string within an array.

One simple way to do this is to use the indexOf() function, which gives you the index a string is found at, or returns -1 when it can't find the string.

Example:

var arr = ['example','foo','bar'];
var str = 'foo';
arr.indexOf(str); //returns 1, because arr[1] == 'foo'

str = 'whatever';
arr.indexOf(str); // returns -1 

Edit 19/10/2017

The introduction of ES6 gives us : arr.includes('str') //true/false

Travel

hey, thank you. but, what if i want the string to be a var from the user? and also, where do i put the code for the match in my function? take a look on the jsfiddle. i am new on node.js , so thanks for your help. – Blatant

in that case, var str = process.argv[2] should do the trick – Travel

try to do that : jsfiddle.net/eyal4/qe0r1z26, and its give me an error. i want it also to print the full str - excectly evrey string that contain this str. its little bit hard i guess, but appreciate your help ! how could i do it clean? – Blatant

Answer 2

In NodeJS, if you are looking to match a partial string in an array of strings you could try this approach:

const strings = ['dogcat', 'catfish']
const matchOn = 'dog'

let matches = strings.filter(s => s.includes(matchOn))

console.log(matches) // ['dogcat']

EDIT: By request how to use in context fiddle provided:

var fs = require('fs');                                           
var location = process.cwd();                                     


var files = getFiles('c:/Program Files/nodejs');                                 
var matches = searchStringInArray('c:/Program Files/nodejs/node_modules/npm/bin', files);


console.log(matches);                                             

function getFiles (dir, files_){                                  
    var str = process.argv[2];                                    
    files_ = files_ || [];                                        
    var files = fs.readdirSync(dir);                              
    for (var i in files){                                         
        var name = dir + '/' + files[i];                          
        if (fs.statSync(name).isDirectory()){                     
            getFiles(name, files_);                               
        } else {                                                  
            files_.push(name);                                    
        }                                                         
    }                                                             

    return files_;                                                
}                                                                 

function searchStringInArray (find, files_) {                     
    return files_.filter(s => s.includes(find))                   

}                                                                 

Vargas

hey, thank you. but, what if i want the string to be a var from the user? and also, where do i put the code for the match in my function? take a look on the jsfiddle. i am new on node.js , so thanks for your help. – Blatant

put it in a function for you. I am returning the list of matches and not a number like you had. Not sure if thats what you meant. – Vargas

ok, thanks, but ive been trying to do that jsfiddle.net/eyal4/qe0r1z26/1 like you said and thats not print nothing. how do i print evrey string that include that string and where do i put that on my code. thanks again – Blatant

Answer 3

Another way is to use some

players = [];

const found = this.players.some(player => player === playerAddress);

if (found) {
    // action
} else {
    // action
}

Methinks