JS written test -- regular expression

1. Remove the space before and after the string

			var str="   hello  "
			var reg=/(^\s+)|(\s+$)/g
			var re=str.replace(reg,"")
			//var re=str.trim()  A string of trim Can also be realized 
			console.log("a"+re+"x")

2. Determine whether the substring exists , If it exists, repeat times

        var str="helloabc"
        var reg=/l/g
        var re=str.match(reg)//null   Or array 
		if(re!==null){
			console.log(" There is , repeated "+re.length+" Time ")
		}else{console.log(" non-existent ")}