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?
你可以使用带有选项的String#localeCompare
sensitivity
Which differences in the strings should lead to non-zero result values. Possible values are:
"base": Only strings that differ in base letters compare as unequal. Examples: a ≠ b, a = á, a = A.
"accent": Only strings that differ in base letters or accents and other diacritic marks compare as unequal. Examples: a ≠ b, a ≠ á, a = A.
"case": Only strings that differ in base letters or case compare as unequal. Examples: a ≠ b, a = á, a ≠ A.
"variant": Strings that differ in base letters, accents and other diacritic marks, or case compare as unequal. Other differences may also be taken into consideration. Examples: a ≠ b, a ≠ á, a ≠ A.
The default is "variant" for usage "sort"; it's locale dependent for usage "search".
numeric
Whether numeric collation should be used, such that "1" < "2" < "10". Possible values are true and false; the default is false. This option can be set through an options property or through a Unicode extension key; if both are provided, the options property takes precedence. Implementations are not required to support this property.
var版本=[" 2.0.1”、“2.0”、“1.0”、“1.0.1”,“2.0.0.1”);
版本。sort((a, b) => a.localeCompare(b, undefined, {numeric: true,灵敏度:'base'}));
console.log(版本);
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
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)
这里有一个面向对象的有趣方法:
function versionString(str) {
var parts = str.split('.');
this.product = parts.length > 0 ? parts[0] * 1 : 0;
this.major = parts.length > 1 ? parts[1] * 1 : 0;
this.minor = parts.length > 2 ? parts[2] * 1 : 0;
this.build = parts.length > 3 ? parts[3] * 1 : 0;
this.compareTo = function(vStr){
vStr = this._isVersionString(vStr) ? vStr : new versionString(vStr);
return this.compare(this, vStr);
};
this.toString = function(){
return this.product + "." + this.major + "." + this.minor + "." + this.build;
}
this.compare = function (str1, str2) {
var vs1 = this._isVersionString(str1) ? str1 : new versionString(str1);
var vs2 = this._isVersionString(str2) ? str2 : new versionString(str2);
if (this._compareNumbers(vs1.product, vs2.product) == 0) {
if (this._compareNumbers(vs1.major, vs2.major) == 0) {
if (this._compareNumbers(vs1.minor, vs2.minor) == 0) {
return this._compareNumbers(vs1.build, vs2.build);
} else {
return this._compareNumbers(vs1.minor, vs2.minor);
}
} else {
return this._compareNumbers(vs1.major, vs2.major);
}
} else {
return this._compareNumbers(vs1.product, vs2.product);
}
};
this._isVersionString = function (str) {
return str !== undefined && str.build !== undefined;
};
this._compareNumbers = function (n1, n2) {
if (n1 > n2) {
return 1;
} else if (n1 < n2) {
return -1;
} else {
return 0;
}
};
}
还有一些测试:
var v1 = new versionString("1.0");
var v2 = new versionString("1.0.1");
var v3 = new versionString("2.0");
var v4 = new versionString("2.0.0.1");
var v5 = new versionString("2.0.1");
alert(v1.compareTo("1.4.2"));
alert(v3.compareTo(v1));
alert(v5.compareTo(v4));
alert(v4.compareTo(v5));
alert(v5.compareTo(v5));