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

最简单的方法是使用localeCompare:

a.localeCompare(b, undefined, { numeric: true, sensitivity: 'base' })

这将返回:

0:版本字符串相等 1: a版本大于b版本 -1:版本b大于版本a

其他回答

你可以遍历每个以句点分隔的字符并将其转换为int类型:

var parts = versionString.split('.');

for (var i = 0; i < parts.length; i++) {
  var value = parseInt(parts[i]);
  // do stuffs here.. perhaps build a numeric version variable?
}
function versionCompare(version1, version2){
                var a = version1.split('.');
                var b = version2.split('.');
                for (var i = 0; i < a.length; ++i) {
                    a[i] = Number(a[i]);
                }
                for (var i = 0; i < b.length; ++i) {
                    b[i] = Number(b[i]);
                }
                var length=a.length;

                for(j=0; j<length; j++){
                    if(typeof b[j]=='undefined')b[j]=0;
                    if (a[j] > b[j]) return true;
                    else if(a[j] < b[j])return false;
                    if(j==length-1 && a[j] >= b[j])return true;
                }             

                return false;
            },

摘自http://java.com/js/deployJava.js:

    // return true if 'installed' (considered as a JRE version string) is
    // greater than or equal to 'required' (again, a JRE version string).
    compareVersions: function (installed, required) {

        var a = installed.split('.');
        var b = required.split('.');

        for (var i = 0; i < a.length; ++i) {
            a[i] = Number(a[i]);
        }
        for (var i = 0; i < b.length; ++i) {
            b[i] = Number(b[i]);
        }
        if (a.length == 2) {
            a[2] = 0;
        }

        if (a[0] > b[0]) return true;
        if (a[0] < b[0]) return false;

        if (a[1] > b[1]) return true;
        if (a[1] < b[1]) return false;

        if (a[2] > b[2]) return true;
        if (a[2] < b[2]) return false;

        return true;
    }
// Return 1 if a > b
// Return -1 if a < b
// Return 0 if a == b
function compare(a, b) {
    if (a === b) {
       return 0;
    }

    var a_components = a.split(".");
    var b_components = b.split(".");

    var len = Math.min(a_components.length, b_components.length);

    // loop while the components are equal
    for (var i = 0; i < len; i++) {
        // A bigger than B
        if (parseInt(a_components[i]) > parseInt(b_components[i])) {
            return 1;
        }

        // B bigger than A
        if (parseInt(a_components[i]) < parseInt(b_components[i])) {
            return -1;
        }
    }

    // If one's a prefix of the other, the longer one is greater.
    if (a_components.length > b_components.length) {
        return 1;
    }

    if (a_components.length < b_components.length) {
        return -1;
    }

    // Otherwise they are the same.
    return 0;
}

console.log(compare("1", "2"));
console.log(compare("2", "1"));

console.log(compare("1.0", "1.0"));
console.log(compare("2.0", "1.0"));
console.log(compare("1.0", "2.0"));
console.log(compare("1.0.1", "1.0"));

基于Idan的精彩回答,下面的函数semverCompare通过了语义版本2.0.0的大多数情况。了解更多要点。

function semverCompare(a, b) {
    if (a.startsWith(b + "-")) return -1
    if (b.startsWith(a + "-")) return  1
    return a.localeCompare(b, undefined, { numeric: true, sensitivity: "case", caseFirst: "upper" })
}

它返回:

-1: a < b 0: a == b 1: a > b