IndexOf function is always returing -1

August 2, 2023

I am using indexOf function to check whether specific string exist in the given array or not but It is giving me "-1" always even though specific string exist in given array. Below is code for same.

var independentLocations = ['/home', '/login','/ImpersonateUser'];
independentLocations.indexOf("/Authorization/ImpersonateUser");

Above code giving result "-1" each time even though "ImpersonateUser" is available in given array.

Please help me in this.

>Solution :

Use Array.prototype.findIndex in combination with:

String.prototype.includes (bug-prone solution) :

const independentLocations = ['/home', '/login','/ImpersonateUser'];
const path = "/Authorization/ImpersonateUser";

const idx = independentLocations.findIndex(x => path.includes(x));

console.log(idx); // 2

Notice: that’s the simplest but might be bug-prone: for example, if you use i.e: "/Authorization/ImpersonateUsers" (notice the "s") it will still retun a matching index.

to make it more precise you might use RegExp.prototype.test():

const independentLocations = ['/home', '/login','/ImpersonateUser'];
const path = "/Authorization/ImpersonateUser";

const idx = independentLocations.findIndex(x => new RegExp(`\\b${x}\\b`).test(path));

console.log(idx); // 2