js中如何判断数组中包含某个特定的值_js数组是否包含某个值
If the JavaScript array contains no such values or items, the methodreturns -1. The JavaScriptArray.indexOf()starts checking a JS array from the start and stops at the end of the array. But users can also add the starting index as the second parameter to start the check from a particula...
console.log("str1.contains(str2)="+str1.contains(str2)); //数组扩展contains适用于数组判断 Array.prototype.contains = function(a) { if ("string" == typeof a || "number" == typeof a) for (var b in this) if (a == this[b]) return ! 0; return ! 1 }; var arr1=["jb51....
regs.push(new Array("item_2","^[\\s\\S]+$","item_2Span","开户银行不能为空","填写正确",true)); regs.push(new Array("item_3","^[\\s\\S]+$","item_3Span","帐号不能为空","填写正确",true)); //regs.push(new Array("PlantArea","^[\\s\\S]+$","PlantAreaSpan","厂...
includes()Check if an array contains the specified element indexOf()Search the array for an element and returns its position isArray()Checks whether an object is an array join()Joins all elements of an array into a string keys()Returns a Array Iteration Object, containing the keys of the ...
In our example, it will returntruesince the array contains an object that hascategoryset as“grocery”. And that’s exactly what I wanted to check!
The includes() is a built-in method of JavaScript that is used to discover whether an element is present in an array or not. It can also be used to find substrings in a string. The returning value of the includes() method is a boolean, which means it eit
Javascript Array contains(value) /**//www.java2s.com* Bool check if an Array contains a value * * * @example ['Hello, world!'].contains('world!') * true * * @return {Bool} Returns bool true/false. */Array.prototype.contains =Array.prototype.contains ||function(value) {for(vari ...
takes all other parameters passed and creates a "grades" array variable that contains them const avgGrade = grades.reduce((acc, curr) => acc + curr, 0) / grades.length; // computes average grade from grades return { firstName: firstName, lastName: lastName, grades: grades, avgGrade: ...
Array.contains 函数 确定指定对象是否是Array对象中的元素。此函数是静态的,可在不创建对象实例的情况下调用。 var itemExists = Array.contains(array, item); 返回值 如果指定对象是数组中的元素,则为true;否则为false。 备注 使用contains函数确定指定对象是否是Array对象中的元素。