JavaScript Array 对象 实例 检测数组site是否包含 runoob : letsite=['runoob','google','taobao'];site.includes('runoob');//truesite.includes('baidu');//false 尝试一下 » 定义和用法 includes() 方法用来判断一个数组是否包含一个指定的值,如果是返回 true,否则false。
JavaScript Array 对象 实例 检测数组site是否包含 runoob : letsite=['runoob','google','taobao'];site.includes('runoob');//truesite.includes('baidu');//false 尝试一下 » 定义和用法 includes() 方法用来判断一个数组是否包含一个指定的值,如果是返回 true,否则false。
includes() includes() 是ES6 的中新标准,用来判断一个数组是否包含一个指定的值,如果包含则返回 true ,否则返回 false。 includes() 接收一个参数,fromIndex ,可以从 fromIndex 的索引处开始查找。 代码语言:txt AI代码解释 ['?', '?', '?'].includes('?') // true ['?', '?', '?'].includes(...
[1, 2, 3].includes(3, 3);// false [1, 2, 3].includes(3, -1);// true [1, 2, NaN].includes(NaN);// true 返回值:返回一个布尔型,判断一个数组是否包含一个指定的值,如果是返回 true,否则false。 JS Array 对象中的includes()方法浏览器的兼容性 js array使用includes()检测数组是否包含...
fruits.includes("Mango"); Try it Yourself » Start the search at position 3: constfruits = ["Banana","Orange","Apple","Mango"]; fruits.includes("Banana",3); Try it Yourself » Description Theincludes()method returnstrueif an array contains a specified value. ...
constisThereAnEel=eel=>{return["eel"].includes(eel);}seaCreatures.findIndex Copy Output -1 ThefindIndex()method is particularly useful when working with arrays containing many items. In this tutorial, we reviewed the major built-in iteration array methods in JavaScript. Iteration methods ope...
我们可以使用Array.includes(Array.includes)重写以上条件句。 functiontest(fruit) {// 把条件提取到数组中constredFruits = ['apple','strawberry','cherry','cranberries'];if(redFruits.includes(fruit)) {console.log('red'); } } AI代码助手复制代码 ...
includes()方法用来判断一个数组是否包含一个指定的值,根据情况返回true否false。 代码语言:javascript 复制 vara=[1,2,3];a.includes(2);// truea.includes(4);// false 语法 代码语言:javascript 复制 arr.includes(searchElement)arr.includes(searchElement,fromIndex) ...
TheindexOf()method is especially useful in arrays that contain many items. lastIndexOf() ThelastIndexOf()method returns the index number of the last instance of an element. We can test on the same example fromindexOf(), which includesbarracudatwice. ...
slice()method is used for slicing, that is, intercepting some of the elements in the array, and then returning a new array, leaving the original array unchanged. slice()method can receive one or two parameters: the start index and end index of the returned element.slice()includes the start...