Does javascript string array contain

Whether the JavaScript string array contains

JavaScript is an object-oriented programming language that is widely used in the field of Web development. String arrays are one of the commonly used data types in JavaScript. In actual development, we often need to determine whether a string is contained in a string array. This article will explain in detail how to use JavaScript to determine the inclusion of a string array.

1. JavaScript string array

In JavaScript, a string array is an ordered collection composed of multiple string elements. You can use the following methods to define a string array:

var strArr = ['apple', 'banana', 'orange'];

You can also use the new Array() method to define a string array:

var strArr = new Array('apple', 'banana', 'orange');

Both of the above methods can create a string array, Their results are the same. In actual development, we usually use the former method to define string arrays.

2. JavaScript string inclusion determination

In JavaScript, to determine whether a string is included in another string, you can use the includes() method of the string. For example:

var str = 'hello world';
var subStr = 'world';
if (str.includes(subStr)) {
    console.log('字符串包含');
} else {
    console.log('字符串不包含');
}

In the above code, use the includes() method to determine whether the string str contains subStr. If the result is true, print "String contains", otherwise print "String does not contain".

In addition to the includes() method, you can also use the indexOf() method to determine whether a string is included in another string. For example:

var str = 'hello world';
var subStr = 'world';
if (str.indexOf(subStr) != -1) {
    console.log('字符串包含');
} else {
    console.log('字符串不包含');
}

In the above code, use the indexOf() method to determine whether the string str contains subStr. If the result is not -1, it means that the string contains it, otherwise it means that the string does not contain it.

3. JavaScript string array inclusion determination

In JavaScript, to determine whether a string is included in a string array, you can use the includes() method or indexOf() method of the array. For example:

var strArr = ['apple', 'banana', 'orange'];
var str = 'banana';
if (strArr.includes(str)) {
    console.log('字符串数组包含');
} else {
    console.log('字符串数组不包含');
}

In the above code, use the includes() method to determine whether the string array strArr contains the string str. If the result is true, it means that the string array contains strings, otherwise it means that the string array does not contain strings.

You can also use the indexOf() method to determine whether the string array contains a string. For example:

var strArr = ['apple', 'banana', 'orange'];
var str = 'banana';
if (strArr.indexOf(str) != -1) {
    console.log('字符串数组包含');
} else {
    console.log('字符串数组不包含');
}

In the above code, use the indexOf() method to determine whether the string array strArr contains the string str. If the result is not -1, it means that the string array contains strings, otherwise it means that the string array does not contain strings.

4. Determining whether a string array in JavaScript contains multiple strings

In JavaScript, to determine whether a string array contains multiple strings, you can use a for loop to traverse the array and determine one by one. For example:

var strArr = ['apple', 'banana', 'orange'];
var subStrArr = ['apple', 'banana'];
var isContain = true;
for (var i = 0; i < subStrArr.length; i++) {
    if (!strArr.includes(subStrArr[i])) {
        isContain = false;
        break;
    }
}
if (isContain) {
    console.log('字符串数组包含');
} else {
    console.log('字符串数组不包含');
}

In the above code, a for loop is used to traverse the string array subStrArr to determine whether each string is included in the string array strArr. If all are included, set the isContain variable to true, which means that the string array strArr contains all the strings in subStrArr. Otherwise, set the isContain variable to false, which means that the string array strArr does not contain all the strings in subStrArr.

5. JavaScript string array contains empty string judgment

In JavaScript, to judge whether a string array contains an empty string, you can use a for loop to traverse the array and judge one by one. For example:

var strArr = ['apple', '', 'orange'];
var isContainEmpty = false;
for (var i = 0; i < strArr.length; i++) {
    if (strArr[i] == '') {
        isContainEmpty = true;
        break;
    }
}
if (isContainEmpty) {
    console.log('字符串数组包含空字符串');
} else {
    console.log('字符串数组不包含空字符串');
}

In the above code, a for loop is used to traverse the string array strArr to determine whether each string is an empty string. If an empty string is found, set the isContainEmpty variable to true, indicating that the string array strArr contains an empty string. Otherwise, set the isContainEmpty variable to false, indicating that the string array strArr does not contain an empty string.

6. Conclusion

JavaScript is an object-oriented programming language and is widely used in the field of Web development. A JavaScript string array is an ordered collection of multiple string elements. To determine whether a string is included in another string, you can use the string's includes() method or indexOf() method. To determine whether a string is included in a string array, you can use the includes() method or indexOf() method of the array. To determine whether a string array contains multiple strings, you can use a for loop to traverse the array and determine one by one. To determine whether a string array contains an empty string, you can also use a for loop to traverse the array and determine one by one. Mastering the inclusion judgment method of JavaScript string array will be of great help to actual development.

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