JSFiddle - React, Tailwind, and code Playground

JavaScript

var x = [{"Address1":"Mbezi Beach, Dar es salaam","searchstr":"Mbezi Beach, Dar es salaam"},
{"Address1":"Regent Estate, Dar es salaam","searchstr":"Regent Estate, Dar es salaam"},{"Address1":"Msasani Peninsula, Dar es salaam","searchstr":"Msasani Peninsula, Dar es salaam"},
         
];

 function getMatches(data,city){
			 var matchArr = [];
             var pattern = RegExp('\\b' + city + '\\b')
		for (var i in data){		
				 var searchStr = data[i].searchstr;
                 if(pattern.test(searchStr)){
                    matchArr.push(data[i]);
                }
			}
			return matchArr;
		}

var arr = getMatches(x,'Dar es');
alert("arr: " + arr.length);