how to remove \ (backslash ) symbol from string using javascript?

Use:

str.replace(/\\/g, "-");

So you need to use backslash (\) instead of forward slash (/).

it should be

var str = 'Visit\\ Microsoft \\';

var res = str.replace(/\\/g, "-");
alert(res);

you need to escape the \ with another \ as back slash is a escape character, also the regex should be /\\/g

Demo: Fiddle

Another approach.

str = str.split('\\').join('').trim()

Have you noticed the color change in your HTML Code?

var str ='Visit\ Microsoft \'; 

var res = str.replace(/\//g, "-");
alert(res);

Everything after Microsoft is red, that indicates everything after Microsoft is also a string.

\ Backslash works as a except character, So it except closing "'" mark.

Please check your code, you may need to add backslash before Space, like below

var str ='Visit\ Microsoft\ '; 

var res = str.replace(/\//g, "-");
alert(res);

This Code will work as you wanted.

var str ='Visit\ Microsoft \'; will not work, coz its invalid..

var str ='Visit\\ Microsoft \\'; -- is the correct js string