Checks if a given string has the expected closing char.

testString.js

const testString = (s)=>{

    console.log('Evaluating string ', s)

    let opening = ['(', '[', '{']
    let closing = [')', ']', '}']

    const findIndex = (list, char) =>{
        for (let i in list)
            if(list[i]===char) return i;
    }

    //s lenght must be even
    if(s.length %2 !== 0) {
        console.log(`String ${s} length is odd.`);  
        return false
    }    

    for (let i = 0; i < s.length; i+=2) {
        let currentChar = s.charAt(i)
        let nextChar = s.charAt(i+1)
        let currentIndex = findIndex(opening, currentChar);
        
        if (nextChar !== closing[currentIndex])
            return false
    } 
    return true;
}

let s1 = "()";
console.log(testString(s1))

let s2 = "()[]{}"
console.log(testString(s2))

let s3 = "(]"
console.log(testString(s3))

let s4 = "()[]{}("
console.log(testString(s4))