JSFiddle - React, Tailwind, and code Playground

by Ryan J

HTML

<a href="#" onclick="foo(1); return false;">Click</a>
<a href="#" onclick="foo(2); return false;">Click</a>
<a href="#" onclick="foo(3); return false;">Click</a>
<br>
<a href="#" onclick="bar(1); return false;">Click</a>
<a href="#" onclick="bar(2); return false;">Click</a>
<a href="#" onclick="bar(3); return false;">Click</a>

JavaScript

var arr_test = [];

function foo(id){
    if(arr_test.indexOf(id) == -1){
        arr_test.push(id);
    }    
    else
        alert("already added.");
    console.log(arr_test);
}

function bar(id){
    if(arr_test.indexOf(id) == -1){
        arr_test.push(id);
    }
    else
        alert("already added.");
    console.log(arr_test);
}