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?
例如,如果我们想检查当前jQuery版本是否小于1.8,如果version是"1.10.1",parseFloat($.ui.version) < 1.8)将会给出错误的结果,因为parseFloat("1.10.1")返回1.1。
字符串比较也会出错,因为"1.8" < "1.10"的结果为false。
所以我们需要一个这样的测试
if(versionCompare($.ui.version, "1.8") < 0){
alert("please update jQuery");
}
下面的函数可以正确地处理这个问题:
/** Compare two dotted version strings (like '10.2.3').
* @returns {Integer} 0: v1 == v2, -1: v1 < v2, 1: v1 > v2
*/
function versionCompare(v1, v2) {
var v1parts = ("" + v1).split("."),
v2parts = ("" + v2).split("."),
minLength = Math.min(v1parts.length, v2parts.length),
p1, p2, i;
// Compare tuple pair-by-pair.
for(i = 0; i < minLength; i++) {
// Convert to integer if possible, because "8" > "10".
p1 = parseInt(v1parts[i], 10);
p2 = parseInt(v2parts[i], 10);
if (isNaN(p1)){ p1 = v1parts[i]; }
if (isNaN(p2)){ p2 = v2parts[i]; }
if (p1 == p2) {
continue;
}else if (p1 > p2) {
return 1;
}else if (p1 < p2) {
return -1;
}
// one operand is NaN
return NaN;
}
// The longer tuple is always considered 'greater'
if (v1parts.length === v2parts.length) {
return 0;
}
return (v1parts.length < v2parts.length) ? -1 : 1;
}
下面是一些例子:
// compare dotted version strings
console.assert(versionCompare("1.8", "1.8.1") < 0);
console.assert(versionCompare("1.8.3", "1.8.1") > 0);
console.assert(versionCompare("1.8", "1.10") < 0);
console.assert(versionCompare("1.10.1", "1.10.1") === 0);
// Longer is considered 'greater'
console.assert(versionCompare("1.10.1.0", "1.10.1") > 0);
console.assert(versionCompare("1.10.1", "1.10.1.0") < 0);
// Strings pairs are accepted
console.assert(versionCompare("1.x", "1.x") === 0);
// Mixed int/string pairs return NaN
console.assert(isNaN(versionCompare("1.8", "1.x")));
//works with plain numbers
console.assert(versionCompare("4", 3) > 0);
看到这里的现场示例和测试套件:
http://jsfiddle.net/mar10/8KjvP/
我认为这是一个值得分享的实现,因为它简短,简单,但功能强大。请注意,它只使用数字比较。通常它会检查version2是否比version1晚,如果是,则返回true。假设您有version1: 1.1.1和version2: 1.1.2。它遍历两个版本的每个部分,将它们的部分相加如下:对于版本1(1 + 0.1)然后(1.1 + 0.01),对于版本2(1 + 0.1)然后(1.1 + 0.02)。
function compareVersions(version1, version2) {
version1 = version1.split('.');
version2 = version2.split('.');
var maxSubVersionLength = String(Math.max.apply(undefined, version1.concat(version2))).length;
var reduce = function(prev, current, index) {
return parseFloat(prev) + parseFloat('0.' + Array(index + (maxSubVersionLength - String(current).length)).join('0') + current);
};
return version1.reduce(reduce) < version2.reduce(reduce);
}
如果你想从版本列表中找到最新的版本,那么这可能是有用的:
function findLatestVersion(versions) {
if (!(versions instanceof Array)) {
versions = Array.prototype.slice.apply(arguments, [0]);
}
versions = versions.map(function(version) { return version.split('.'); });
var maxSubVersionLength = String(Math.max.apply(undefined, Array.prototype.concat.apply([], versions))).length;
var reduce = function(prev, current, index) {
return parseFloat(prev) + parseFloat('0.' + Array(index + (maxSubVersionLength - String(current).length)).join('0') + current);
};
var sums = [];
for (var i = 0; i < versions.length; i++) {
sums.push(parseFloat(versions[i].reduce(reduce)));
}
return versions[sums.indexOf(Math.max.apply(undefined, sums))].join('.');
}
console.log(findLatestVersion('0.1000000.1', '2.0.0.10', '1.6.10', '1.4.3', '2', '2.0.0.1')); // 2.0.0.10
console.log(findLatestVersion(['0.1000000.1', '2.0.0.10', '1.6.10', '1.4.3', '2', '2.0.0.1'])); // 2.0.0.10
我也遇到过类似的问题,而且我已经为它创建了一个解决方案。你可以试一试。
如果等于则返回0,如果版本号大于则返回1,如果版本号小于则返回-1
function compareVersion(currentVersion, minVersion) {
let current = currentVersion.replace(/\./g," .").split(' ').map(x=>parseFloat(x,10))
let min = minVersion.replace(/\./g," .").split(' ').map(x=>parseFloat(x,10))
for(let i = 0; i < Math.max(current.length, min.length); i++) {
if((current[i] || 0) < (min[i] || 0)) {
return -1
} else if ((current[i] || 0) > (min[i] || 0)) {
return 1
}
}
return 0
}
console.log(compareVersion("81.0.1212.121","80.4.1121.121"));
console.log(compareVersion("81.0.1212.121","80.4.9921.121"));
console.log(compareVersion("80.0.1212.121","80.4.9921.121"));
console.log(compareVersion("4.4.0","4.4.1"));
console.log(compareVersion("5.24","5.2"));
console.log(compareVersion("4.1","4.1.2"));
console.log(compareVersion("4.1.2","4.1"));
console.log(compareVersion("4.4.4.4","4.4.4.4.4"));
console.log(compareVersion("4.4.4.4.4.4","4.4.4.4.4"));
console.log(compareVersion("0","1"));
console.log(compareVersion("1","1"));
console.log(compareVersion("1","1.0.00000.0000"));
console.log(compareVersion("","1"));
console.log(compareVersion("10.0.1","10.1"));
如果不允许使用字母或符号,那么代码行数就很少。如果您控制了版本控制方案,并且不是第三方提供的,那么这种方法是有效的。
// we presume all versions are of this format "1.4" or "1.10.2.3", without letters
// returns: 1 (bigger), 0 (same), -1 (smaller)
function versionCompare (v1, v2) {
const v1Parts = v1.split('.')
const v2Parts = v2.split('.')
const length = Math.max(v1Parts.length, v2Parts.length)
for (let i = 0; i < length; i++) {
const value = (parseInt(v1Parts[i]) || 0) - (parseInt(v2Parts[i]) || 0)
if (value < 0) return -1
if (value > 0) return 1
}
return 0
}
console.log(versionCompare('1.2.0', '1.2.4') === -1)
console.log(versionCompare('1.2', '1.2.0') === 0)
console.log(versionCompare('1.2', '1') === 1)
console.log(versionCompare('1.2.10', '1.2.1') === 1)
console.log(versionCompare('1.2.134230', '1.2.2') === 1)
console.log(versionCompare('1.2.134230', '1.3.0.1.2.3.1') === -1)
这是一个巧妙的技巧。如果您正在处理数值,在特定的值范围内,您可以为版本对象的每个级别分配一个值。例如,“largestValue”在这里被设置为0xFF,这为您的版本控制创建了一个非常“IP”的外观。
这也处理字母-数字版本(即1.2a < 1.2b)
// The version compare function
function compareVersion(data0, data1, levels) {
function getVersionHash(version) {
var value = 0;
version = version.split(".").map(function (a) {
var n = parseInt(a);
var letter = a.replace(n, "");
if (letter) {
return n + letter[0].charCodeAt() / 0xFF;
} else {
return n;
}
});
for (var i = 0; i < version.length; ++i) {
if (levels === i) break;
value += version[i] / 0xFF * Math.pow(0xFF, levels - i + 1);
}
return value;
};
var v1 = getVersionHash(data0);
var v2 = getVersionHash(data1);
return v1 === v2 ? -1 : v1 > v2 ? 0 : 1;
};
// Returns 0 or 1, correlating to input A and input B
// Direct match returns -1
var version = compareVersion("1.254.253", "1.254.253a", 3);