Regular expression to remove spaces

1. Remove the left space.replace (/^\s*/g,"");

2 Remove the space on the right.replace (/\s*$/g,"");

3 Remove the spaces before and after.replace(/(^\s*)|(\s*$)/g,"")

4 Remove all spaces.replace (/\s+/g,"")

Blank test: <input type="text" id="test" name="text" onchange="blank();" ><br>

<script>
$(function(){
var test =$('#test').val();

alert(test);

})

function blank(){
var test =$('#test').val();
<%--remove the space on the left --%>
alert("a"+test);
test = test.replace(/^\s*/g,"");
alert("Remove the left space"+test); 

<%--Remove the space on the right--%>
alert(test+"a"); 
test = test.replace(/\s*$/g,"");
alert(test+"Remove the space on the right"); 

<%--Remove spaces before and after the string--%>
test = test.replace(/(^\s*)|(\s*$)/g, "");
alert("Remove the spaces before and after the string"+test+"a");
 
<%--Remove all spaces in the string--%>
test = test.replace(/\s+/g,"");
alert("a"+test+"a");
}

</script>