JavaScript intercepts strings (implemented through substring and supports mixed in Chinese and English) _javascript tips

JavaScript intercept string (supports mixed in Chinese and English)

Copy Code code as follows:

<script type= "Text/javascript" >
var sub=function (str,n) {
var r=/[^\x00-\xff]/g;
if (Str.replace (R, "MM"). length<=n) {return str;}
var m=math.floor (N/2);
for (Var i=m;i<str.length;i++) {
if (Str.substr (0,i). Replace (R, "MM"). Length>=n) {
Return Str.substr (0,i) + "...";
}
}
return str;
}
Alert (sub (' String intercepts the JavaScript processing summary (JS intercept Chinese string summary) ', 15))
</script>

Using JS method substring ()

Copy Code code as follows:

var str = "0123456789";
Alert (str.substring (0));------------"0123456789"
Alert (str.substring (5));------------"56789"
alert (str.substring);-----------""
alert (str.substring);-----------""
Alert (str.substring ( -5));-----------"0123456789"
Alert (str.substring ( -10));----------"0123456789"
Alert (str.substring ( -12));----------"0123456789"
Alert (str.substring (0,5));----------"01234"
Alert (str.substring (0,10));---------"0123456789"
Alert (str.substring (0,12));---------"0123456789"
Alert (str.substring (2,0));----------"01"
Alert (str.substring (2,2));----------""
Alert (str.substring (2,5));----------"234"
Alert (str.substring (2,12));---------"23456789"
Alert (str.substring (2,-2));---------"01"
Alert (str.substring ( -1,5));---------"01234"
Alert (str.substring ( -1,-5));--------""

Using JS method substr ()

Copy code code as follows:

var str = "0123456789";
Alert (str.substr (0)),---------------"0123456789"
Alert (STR.SUBSTR (5)),---------------"56789"
Alert ( STR.SUBSTR)--------------""
Alert (STR.SUBSTR),--------------""
Alert (Str.substr ( -5));---------- ----"0123456789"
Alert (Str.substr ( -10)),-------------"0123456789"
Alert (Str.substr ( -12)),-------------" 0123456789
Alert (str.substr (0,5)),-------------"01234"
Alert (Str.substr (0,10)),------------"0123456789"
Alert (STR.SUBSTR (0,12)),------------"0123456789"
Alert (Str.substr (2,0)),-------------""
Alert ( Str.substr (2,2)),-------------"a"
Alert (str.substr (2,5)),-------------"23456"
Alert (Str.substr (2,12));- -----------"23456789"
Alert (Str.substr (2,-2)),------------""
Alert (Str.substr ( -1,5)),------------"01234"
Alert (STR.SUBSTR ( -1,-5));-----------"