Determine whether it follows the sequence given in the patterns array

areFollowingPatterns.js

// Given an array strings, determine whether it follows the sequence given in the patterns array. In other words, there should be no i and j for which strings[i] = strings[j] and patterns[i] ≠ patterns[j] or for which strings[i] ≠ strings[j] and patterns[i] = patterns[j].

function areFollowingPatterns(strings, patterns) {

    let sHash = {}
    let pHash = {}
    
    let counter = 0
    
    let pat1 = ''
    let pat2 = ''
    
    for(let i=0; i<strings.length; i++){
        
        if(sHash[strings[i]]===pHash[patterns[i]]){
            
            counter++
            
            if(!sHash[strings[i]]){
                
                sHash[strings[i]] = counter
            } 

            if(!pHash[patterns[i]]){
                
                pHash[patterns[i]] = counter
            }  

            pat1 += sHash[strings[i]]
            pat2 += pHash[patterns[i]]

        }else{
            return false
        }
        
        if(pat1 !== pat2){return false}
    
    }
    
    return true
}