JSFiddle - React, Tailwind, and code Playground

HTML

<p id='display'></p>

JavaScript

t = [
	2,
	4,
	1.2,
	1.2345,
	0.2,
	0.234,
	0,
	1023.123
];

t.forEach(function(v){
	var vv = ('' + v).replace(/(\.\d+)?$/, function(a, b){//用正则匹配小数部分, 如果匹配不到,就返回 .0 匹配到就返回原来的
		return b || '.0';
	});

	$('#display').append('<pre>' + v + '\t' + vv + '</pre>');
});