Just to demonstrate the flexibility
of javascript: you can use a oneliner for this
function padLeft(nr, n, str){
return Array(n-String(nr).length+1).join(str||'0')+nr;
}
//or as a Number prototype
method:
Number.prototype.padLeft = function(n,str){
return Array(n-String(this).length+1).join(str||'0')+this;
}
//examples
console.log(padLeft(23,5)); //=> '00023'
console.log((23).padLeft(5)); //=> '00023'
console.log((23).padLeft(5,' ')); //=> ' 23'
console.log(padLeft(23,5,'>>')); //=> '>>>>>>23'
If you want to use this for negative
numbers also:
Number.prototype.padLeft = function(n,str){
return (this < 0 ? '-' : '') +
Array(n-String(Math.abs(this)).length+1)
.join(str||'0') +
(Math.abs(this));
}
console.log((-23).padLeft(5)); //=> '-00023'
