如何在特殊字符之前的字符串中添加更多文本

Question

I would like to modify a string using jQuery as following:

Existing value: myimage_one.png
New value: myimage_one_notold.png

How can I do it? Maybe with the concat() function?

Answer 1

You can use the replace() function on your string. In this case you could replace the .png with _notold.png :

 var foo = 'myimage_one.png'; var bar = foo.replace('.png', '_notold.png'); console.log(bar); 

Alternatively, you can use this regular expression if you want to only remove the last instance of the . , in cases where the filename contains more than one:

 var foo = 'myimage_one.png'; var bar = foo.replace(/\\.([^\\.]*)$/,'_notold.$1'); console.log(bar); 

Also note that both of the above use native JS methods and havenothing to do with jQuery

Answer 2

function replaceString(org_str,replace_with)
{   
var found_str = org_str.substring(org_str.lastIndexOf('.') + 1); 
return org_str.replace(found_str, replace_with);    
}

Answer 3

if you always want to append the string before the last . you can use split:

http://www.w3schools.com/jsref/jsref_split.asp

var strArr = existingVar.split('.');
var newString = "";
for (var i = 0; i < strArr.length; i++) {
    if (i+1 < strArr.length) {
    newString += strArr[i];
    } else {
        newString += "_notOld"+ strArr[i+1];     
    }
}
alert(newString);

this should do the job in every case, with each filetype and name (for example: my.new.file.is.cool.jpg should work as well as myFile.png or myImage.yeah.gif )

Answer 4

假设您在文件名的最后一个点之后有任何字母，数字，下划线或破折号，然后：

filename = filename.replace(/(\\.[\\w\\d_-]+)$/i, '_notold$1');

Answer 5

You can do the changes using the following method,

var existingVal = "myimage_one.png";
var modifiedVal = exisitingVal.replace(".","_notold.");