src/string/xpad.js
function padding(size,ch){
    var str = '';
    if(!ch && ch !== 0){
        ch = ' ';
    }
    while(size !== 0){
        if(size & 1 === 1){
            str += ch;
        }
        ch += ch;
        size >>>= 1;
    }
    return str;
}
function padding(size,ch){
    var str = '';
    if(!ch && ch !== 0){
        ch = ' ';
    }
    while(size !== 0){
        if(size & 1 === 1){
            str += ch;
        }
        ch += ch;
        size >>>= 1;
    }
    return str;
}
function padding ( size , ch ) { var str = '' ; if ( ! ch && ch !== 0 ) { ch = ' ' ; } while ( size !== 0 ) { if ( size & 1 === 1 ) { str += ch ; } ch += ch ; size >>>= 1 ; } return str ; }
return a string by repeat a char n times
return a string by repeat a char n times