文本长度超过3个字符串，而不是用另一个字符串替换rest

Question

How to replace the rest of a string more than 3 character swith another character?

ex :

var str = "John Doe";

I want output with

Johxxxxx

Answer 1

Use String#replace method with a callback function

 var str = "John Doe"; console.log( str.replace(/^(.{3})(.+)$/, function(_, m1, m2) { return m1 + // first 3 characters new Array(m2.length + 1).join('x'); // generate string with length of remaining character }) ) 

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Or use String#slice method.

 var str = "John Doe"; console.log( str.slice(0, 3) + // get first three character new Array(str.length > 2 ? str.length - 2 : 0).join('x') // generate string with remaining length )