以下是软件版本号:
"1.0", "1.0.1", "2.0", "2.0.0.1", "2.0.1"
我怎么比较呢?
假设正确的顺序是:
"1.0", "1.0.1", "2.0", "2.0.0.1", "2.0.1"
想法很简单… 读第一个数字，然后，第二个，第三个… 但是我不能将版本号转换为浮点数… 你也可以像这样看到版本号:
"1.0.0.0", "1.0.1.0", "2.0.0.0", "2.0.0.1", "2.0.1.0"
这样可以更清楚地看到背后的想法。 但是，我怎样才能把它转换成计算机程序呢?
当前回答
这里找不到我想要的函数。所以我自己写了。这就是我的贡献。我希望有人觉得它有用。
优点:
处理任意长度的版本字符串。'1'或'1.1.1.1.1'。 如果没有指定，则默认为0。仅仅因为字符串更长并不意味着它是一个更大的版本。(“1”应与“1.0”和“1.0.0.0”相同。) 比较数字而不是字符串。('3'<'21'应为真。不是假的。) 不要把时间浪费在无用的比较上。(比较for ==) 你可以选择你自己的比较器。
缺点:
它不处理版本字符串中的字母。(我不知道这是怎么回事?)
我的代码，类似于Jon接受的答案:
function compareVersions(v1, comparator, v2) {
"use strict";
var comparator = comparator == '=' ? '==' : comparator;
if(['==','===','<','<=','>','>=','!=','!=='].indexOf(comparator) == -1) {
throw new Error('Invalid comparator. ' + comparator);
}
var v1parts = v1.split('.'), v2parts = v2.split('.');
var maxLen = Math.max(v1parts.length, v2parts.length);
var part1, part2;
var cmp = 0;
for(var i = 0; i < maxLen && !cmp; i++) {
part1 = parseInt(v1parts[i], 10) || 0;
part2 = parseInt(v2parts[i], 10) || 0;
if(part1 < part2)
cmp = 1;
if(part1 > part2)
cmp = -1;
}
return eval('0' + comparator + cmp);
}
例子:
compareVersions('1.2.0', '==', '1.2'); // true
compareVersions('00001', '==', '1.0.0'); // true
compareVersions('1.2.0', '<=', '1.2'); // true
compareVersions('2.2.0', '<=', '1.2'); // false
其他回答
这是另一种递归算法。
这段代码只使用了Array。shift和递归，这意味着它可以在Internet Explorer 6+中运行。如果你有任何疑问，你可以访问我的GitHub页面。
(function(root, factory) {
if (typeof exports === 'object') {
return module.exports = factory();
} else if (typeof define === 'function' && define.amd) {
return define(factory);
} else {
return root.compareVer = factory();
}
})(this, function() {
'use strict';
var _compareVer;
_compareVer = function(newVer, oldVer) {
var VER_RE, compareNum, isTrue, maxLen, newArr, newLen, newMatch, oldArr, oldLen, oldMatch, zerofill;
VER_RE = /(\d+\.){1,9}\d+/;
if (arguments.length !== 2) {
return -100;
}
if (typeof newVer !== 'string') {
return -2;
}
if (typeof oldVer !== 'string') {
return -3;
}
newMatch = newVer.match(VER_RE);
if (!newMatch || newMatch[0] !== newVer) {
return -4;
}
oldMatch = oldVer.match(VER_RE);
if (!oldMatch || oldMatch[0] !== oldVer) {
return -5;
}
newVer = newVer.replace(/^0/, '');
oldVer = oldVer.replace(/^0/, '');
if (newVer === oldVer) {
return 0;
} else {
newArr = newVer.split('.');
oldArr = oldVer.split('.');
newLen = newArr.length;
oldLen = oldArr.length;
maxLen = Math.max(newLen, oldLen);
zerofill = function() {
newArr.length < maxLen && newArr.push('0');
oldArr.length < maxLen && oldArr.push('0');
return newArr.length !== oldArr.length && zerofill();
};
newLen !== oldLen && zerofill();
if (newArr.toString() === oldArr.toString()) {
if (newLen > oldLen) {
return 1;
} else {
return -1;
}
} else {
isTrue = -1;
compareNum = function() {
var _new, _old;
_new = ~~newArr.shift();
_old = ~~oldArr.shift();
_new > _old && (isTrue = 1);
return _new === _old && newArr.length > 0 && compareNum();
};
compareNum();
return isTrue;
}
}
};
return _compareVer;
});
好吧，我希望这段代码能帮助到一些人。
下面是测试。
console.log(compareVer("0.0.2","0.0.1"));//1
console.log(compareVer("0.0.10","0.0.1")); //1
console.log(compareVer("0.0.10","0.0.2")); //1
console.log(compareVer("0.9.0","0.9")); //1
console.log(compareVer("0.10.0","0.9.0")); //1
console.log(compareVer("1.7", "1.07")); //1
console.log(compareVer("1.0.07", "1.0.007")); //1
console.log(compareVer("0.3","0.3")); //0
console.log(compareVer("0.0.3","0.0.3")); //0
console.log(compareVer("0.0.3.0","0.0.3.0")); //0
console.log(compareVer("00.3","0.3")); //0
console.log(compareVer("00.3","00.3")); //0
console.log(compareVer("01.0.3","1.0.3")); //0
console.log(compareVer("1.0.3","01.0.3")); //0
console.log(compareVer("0.2.0","1.0.0")); //-1
console.log(compareVer('0.0.2.2.0',"0.0.2.3")); //-1
console.log(compareVer('0.0.2.0',"0.0.2")); //-1
console.log(compareVer('0.0.2',"0.0.2.0")); //-1
console.log(compareVer("1.07", "1.7")); //-1
console.log(compareVer("1.0.007", "1.0.07")); //-1
console.log(compareVer()); //-100
console.log(compareVer("0.0.2")); //-100
console.log(compareVer("0.0.2","0.0.2","0.0.2")); //-100
console.log(compareVer(1212,"0.0.2")); //-2
console.log(compareVer("0.0.2",1212)); //-3
console.log(compareVer('1.abc.2',"1.0.2")); //-4
console.log(compareVer('1.0.2',"1.abc.2")); //-5
两个版本比较
const val = '1.2.3 5.4.3';
const arr = val.split(' ');
let obj = {};
for(let i = 0; i<2; i++) {
const splitArr = arr[i].split('.')
const reduced = splitArr.reduce((pre,
curr)=>parseInt(pre)+parseInt(curr));
obj[i] = reduced;
}
if(obj[0]>obj[1]) {
console.log(arr[0]);
} else {
console.log(arr[1]);
}
// Returns true if v1 is bigger than v2, and false if otherwise.
function isNewerThan(v1, v2) {
v1=v1.split('.');
v2=v2.split('.');
for(var i = 0; i<Math.max(v1.length,v2.length); i++){
if(v1[i] == undefined) return false; // If there is no digit, v2 is automatically bigger
if(v2[i] == undefined) return true; // if there is no digit, v1 is automatically bigger
if(v1[i] > v2[i]) return true;
if(v1[i] < v2[i]) return false;
}
return false; // Returns false if they are equal
}
下面是一个版本，它对版本字符串进行排序，而不分配任何子字符串或数组。由于它分配的对象更少，GC要做的工作也就更少。
有一对分配(允许重用getVersionPart方法)，但是如果您对性能非常敏感，您可以扩展它以完全避免分配。
const compareVersionStrings : (a: string, b: string) => number = (a, b) =>
{
var ia = {s:a,i:0}, ib = {s:b,i:0};
while (true)
{
var na = getVersionPart(ia), nb = getVersionPart(ib);
if (na === null && nb === null)
return 0;
if (na === null)
return -1;
if (nb === null)
return 1;
if (na > nb)
return 1;
if (na < nb)
return -1;
}
};
const zeroCharCode = '0'.charCodeAt(0);
const getVersionPart = (a : {s:string, i:number}) =>
{
if (a.i >= a.s.length)
return null;
var n = 0;
while (a.i < a.s.length)
{
if (a.s[a.i] === '.')
{
a.i++;
break;
}
n *= 10;
n += a.s.charCodeAt(a.i) - zeroCharCode;
a.i++;
}
return n;
}
replace()函数只替换字符串中的第一个出现项。我们来替换。与,。然后全部删除。然后做，to。再次将其解析为float。
for(i=0; i<versions.length; i++) {
v = versions[i].replace('.', ',');
v = v.replace(/\./g, '');
versions[i] = parseFloat(v.replace(',', '.'));
}
最后，排序:
versions.sort();
