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

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/

其他回答

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();

我不喜欢任何一个解决方案,所以我根据自己的编码偏好重新编写了它。请注意,最后四个检查结果与接受的答案略有不同。对我有用。

function v_check(version_a, version_b) {
    // compares version_a as it relates to version_b
    // a = b => "same"
    // a > b => "larger"
    // a < b => "smaller"
    // NaN   => "invalid"

    const arr_a = version_a.split('.');
    const arr_b = version_b.split('.');

    let result = "same"; // initialize to same // loop tries to disprove

    // loop through a and check each number against the same position in b
    for (let i = 0; i < arr_a.length; i++) {
        let a = arr_a[i];
        let b = arr_b[i];

        // same up to this point so if a is not there, a is smaller
        if (typeof a === 'undefined') {
            result = "smaller";
            break;

        // same up to this point so if b is not there, a is larger
        } else if (typeof b === 'undefined') {
            result = "larger";
            break;

        // otherwise, compare the two numbers
        } else {

            // non-positive numbers are invalid
            if (a >= 0 && b >= 0) {

                if (a < b) {
                    result = "smaller";
                    break;
                }
                else if (a > b) {
                    result = "larger";
                    break;
                }

            } else {
                result = "invalid";
                break;
            }
        }
    }

    // account for the case where the loop ended but there was still a position in b to evaluate
    if (result == "same" && arr_b.length > arr_a.length) result = "smaller";

    return result;
}


console.log(v_check("1.7.1", "1.7.10"));  // smaller
console.log(v_check("1.6.1", "1.7.10"));  // smaller
console.log(v_check("1.6.20", "1.7.10")); // smaller
console.log(v_check("1.7.1", "1.7.10"));  // smaller
console.log(v_check("1.7", "1.7.0"));     // smaller
console.log(v_check("1.7", "1.8.0"));     // smaller

console.log(v_check("1.7.10", "1.7.1"));  // larger
console.log(v_check("1.7.10", "1.6.1"));  // larger
console.log(v_check("1.7.10", "1.6.20")); // larger
console.log(v_check("1.7.0", "1.7"));     // larger
console.log(v_check("1.8.0", "1.7"));     // larger

console.log(v_check("1.7.10", "1.7.10")); // same
console.log(v_check("1.7", "1.7"));       // same

console.log(v_check("1.7", "1..7")); // larger
console.log(v_check("1.7", "Bad"));  // invalid
console.log(v_check("1..7", "1.7")); // smaller
console.log(v_check("Bad", "1.7"));  // invalid

这适用于由句点分隔的任何长度的数字版本。只有当myVersion为>= minimumVersion时,它才返回true,假设版本1小于1.0,版本1.1小于1.1.0,以此类推。添加额外的条件应该相当简单,比如接受数字(只需转换为字符串)和十六进制,或者使分隔符动态(只需添加一个分隔符参数,然后将“。”替换为参数)

function versionCompare(myVersion, minimumVersion) {

    var v1 = myVersion.split("."), v2 = minimumVersion.split("."), minLength;   

    minLength= Math.min(v1.length, v2.length);

    for(i=0; i<minLength; i++) {
        if(Number(v1[i]) > Number(v2[i])) {
            return true;
        }
        if(Number(v1[i]) < Number(v2[i])) {
            return false;
        }           
    }

    return (v1.length >= v2.length);
}

下面是一些测试:

console.log(versionCompare("4.4.0","4.4.1"));
console.log(versionCompare("5.24","5.2"));
console.log(versionCompare("4.1","4.1.2"));
console.log(versionCompare("4.1.2","4.1"));
console.log(versionCompare("4.4.4.4","4.4.4.4.4"));
console.log(versionCompare("4.4.4.4.4.4","4.4.4.4.4"));
console.log(versionCompare("0","1"));
console.log(versionCompare("1","1"));
console.log(versionCompare("","1"));
console.log(versionCompare("10.0.1","10.1"));

这里有一个递归版本

function versionCompare(myVersion, minimumVersion) {
  return recursiveCompare(myVersion.split("."),minimumVersion.split("."),Math.min(myVersion.length, minimumVersion.length),0);
}

function recursiveCompare(v1, v2,minLength, index) {
  if(Number(v1[index]) < Number(v2[index])) {
    return false;
  }
  if(Number(v1[i]) < Number(v2[i])) {
    return true;
    }
  if(index === minLength) {
    return (v1.length >= v2.length);
  }
  return recursiveCompare(v1,v2,minLength,index+1);
}
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;
            },
function compare(versionA: string | undefined, versionB: string | undefined, operator: string = '>') {
    if (versionA === undefined || versionB === undefined) {
        return false
    }
    const listA = versionA.split('.')
    const listB = versionB.split('.')
    let a = []
    let b = []
    for (let i = 0; i < listA.length; i++) {
        a.push(parseInt(listA[i].replace(/\D/g, ''), 10))
        b.push(parseInt(listB[i].replace(/\D/g, ''), 10))
    }

    for (let i = 0; i < listA.length; i++) {
        switch (operator) {
            case '>':
            case '>=':
                if (a[i] === b[i]) {
                    continue
                }
                if (a[i] > b[i]) {
                    return true
                }
                if (a[i] < b[i]) {
                    return false
                }
                break
            case '<':
            case '<=':
                if (a[i] === b[i]) {
                    continue
                }
                if (a[i] > b[i]) {
                    return false
                }
                if (a[i] < b[i]) {
                    return true
                }
                break
            case '=':
               if (a[i] > b[i]) {
                   return false
               }
               if (a[i] < b[i]) {
                   return false
               }
               break
        }
    }
    switch (operator) {
        case '>':
            return false
        case '<':
            return false
        case '=':
        case '>=':
        case '<=':
            return true
    }
}