// Setup
var testString = "Ada Lovelace and Charles Babbage designed the first computer and the software that would have run on it.";


// 举例
var expressionToGetSoftware = /software/gi;
var softwareCount = testString.match(expressionToGetSoftware).length;




// Only change code below this line.


var expression = /and/gi;// Change this Line


// Only change code above this line


// This code counts the matches of expression in testString
var andCount = testString.match(expression).length;