只是想知道,是否有一种方法可以向.includes方法添加多个条件,例如:
var value = str.includes("hello", "hi", "howdy");
想象一下逗号表示“或”。
它现在询问字符串是否包含hello, hi或howdy。所以只有当其中一个条件为真。
有什么方法可以做到吗?
只是想知道,是否有一种方法可以向.includes方法添加多个条件,例如:
var value = str.includes("hello", "hi", "howdy");
想象一下逗号表示“或”。
它现在询问字符串是否包含hello, hi或howdy。所以只有当其中一个条件为真。
有什么方法可以做到吗?
当前回答
您可以使用这里引用的.some方法。
some()方法测试数组中是否至少有一个元素 通过由提供的函数实现的测试。
// test cases const str1 = 'hi hello, how do you do?'; const str2 = 'regular string'; const str3 = 'hello there'; // do the test strings contain these terms? const conditions = ["hello", "hi", "howdy"]; // run the tests against every element in the array const test1 = conditions.some(el => str1.includes(el)); const test2 = conditions.some(el => str2.includes(el)); // strictly check that contains 1 and only one match const test3 = conditions.reduce((a,c) => a + str3.includes(c), 0) == 1; // display results console.log(`Loose matching, 2 matches "${str1}" => ${test1}`); console.log(`Loose matching, 0 matches "${str2}" => ${test2}`); console.log(`Exact matching, 1 matches "${str3}" => ${test3}`);
另外,正如下面一位用户提到的那样,匹配上面提到的“恰好一个”外观也很有趣(这是OP要求的)。这可以类似地用.reduce计算交点,然后检查它们是否等于1。
其他回答
const givenArray = ['Hi, how are you', 'how are you', 'howdy, how you doing'] const includeValues = ["hello", "hi", "howdy"] const filteredStrArray = givenArray。filter(str => includeValues)str.toLowerCase().includes(value))) console.log (filteredStrArray);
扩展字符串本机原型:
if (!String.prototype.contains) {
Object.defineProperty(String.prototype, 'contains', {
value(patterns) {
if (!Array.isArray(patterns)) {
return false;
}
let value = 0;
for (let i = 0; i < patterns.length; i++) {
const pattern = patterns[i];
value = value + this.includes(pattern);
}
return (value === 1);
}
});
}
允许你做以下事情:
console.log('Hi, hope you like this option'.toLowerCase().contains(["hello", "hi", "howdy"])); // True
您可以使用这里引用的.some方法。
some()方法测试数组中是否至少有一个元素 通过由提供的函数实现的测试。
// test cases const str1 = 'hi hello, how do you do?'; const str2 = 'regular string'; const str3 = 'hello there'; // do the test strings contain these terms? const conditions = ["hello", "hi", "howdy"]; // run the tests against every element in the array const test1 = conditions.some(el => str1.includes(el)); const test2 = conditions.some(el => str2.includes(el)); // strictly check that contains 1 and only one match const test3 = conditions.reduce((a,c) => a + str3.includes(c), 0) == 1; // display results console.log(`Loose matching, 2 matches "${str1}" => ${test1}`); console.log(`Loose matching, 0 matches "${str2}" => ${test2}`); console.log(`Exact matching, 1 matches "${str3}" => ${test3}`);
另外,正如下面一位用户提到的那样,匹配上面提到的“恰好一个”外观也很有趣(这是OP要求的)。这可以类似地用.reduce计算交点,然后检查它们是否等于1。
另一个!
let result const givenStr = 'A, X' //values separated by comma or space. const allowed = ['A', 'B'] const given = givenStr.split(/[\s,]+/).filter(v => v) console.log('given (array):', given) // given contains none or only allowed values: result = given.reduce((acc, val) => { return acc && allowed.includes(val) }, true) console.log('given contains none or only allowed values:', result) // given contains at least one allowed value: result = given.reduce((acc, val) => { return acc || allowed.includes(val) }, false) console.log('given contains at least one allowed value:', result)
即使有且只有一个条件为真,它也能工作:
var str = "bonjour le monde vive le javascript";
var arr = ['bonjour','europe', 'c++'];
function contains(target, pattern){
var value = 0;
pattern.forEach(function(word){
value = value + target.includes(word);
});
return (value === 1)
}
console.log(contains(str, arr));