一、length JavaScript中Array的length属性非常有特点一一它不是只读的。因此,通过设置这个属性可以从数组的末尾移除项或添加新项,请看下面例子: 1 var colors = ["red", "blue", "grey"]; //创建一个包含3个字符串的数组 2 colors.length = 2; 3 console.log(colors[2]); //undefined 二、delete关键...
> let array = ["a", "b", "c"]; > array.pop(); 'c' > array; [ 'a', 'b' ]Using delete creates empty spotsWhatever you do, don't use delete to remove an item from an array. JavaScript language specifies that arrays are sparse, i.e., they can have holes in them....
setLegs(legs) { if (!Array.isArray(legs)) { thrownewError('"legs" is not an array') } this.legs = legs returnthis } setScent(scent) { this.scent = scent returnthis } updateTongueWidthFieldName(tongue) { constnewTongue= { ...tongue } delete newTongue['tongueWidth'] newTongue.wid...
let arrayName = switchNode.discriminant.object.name; // 获取控制流数组绑定的节点 let bindingArray = path.scope.getBinding(arrayName); // 获取节点整个表达式的参数、分割方法、分隔符 let init = bindingArray.path.node.init; let object = init.callee.object.value; let property = init.callee.prope...
// Two slashes start single-line commentsvarx;// declaring a variablex=3+y;// assigning a value to the variable `x`foo(x,y);// calling function `foo` with parameters `x` and `y`obj.bar(3);// calling method `bar` of object `obj`// A conditional statementif(x===0){// Is...
--- String --- Array [ "India", "Russia" ] --- Number --- Array(4) [ 1, 3, 5, 7 ] --- Object --- Name: Bheem, Age: 25 Name: Nakul, Age: 23 Remove from Array with delete Operator JavaScript delete operator removes a property from an object and becomes undefined. When d...
3.ES6还在Array这个全局对象上添加了2个方法 1interface ArrayConstructor {2/**3* Creates an array from an iterable object.4* @param iterable An iterable object to convert to an array.5*/6from<T>(iterable: Iterable<T> | ArrayLike<T>): T[];78/**9* Creates an array from an iterable ...
1,to:5};// 1. for..of 调用首先会调用这个:range[Symbol.iterator]=function(){// ……它返回迭代器对象(iterator object):// 2. 接下来,for..of 仅与此迭代器一起工作,要求它提供下一个值return{current:this.from,last:this.to,// 3. next() 在 for..of 的每一轮循环迭代中被调用next(){...
The delete Operator The semantically correct way to delete a property from an object is the delete operator. Let's see it in action: const student = { name: "Jane", age: 16, score: { maths: 95, science: 90 } } // Deleting a property from an object delete student.age delete studen...
deletearray[2]; /*Expectedresult--[1,2,4] *Actualresult--[1,2,null,4] 4、数组中使用splice arrayObject.splice(index,howmany,item1,...,itemX) index:必需。整数,规定添加/删除项目的位置,使用负数可从数组结 尾处规定位置。 howmany:必需。要删除的项目数量。如果设置为0,则不会删除项目。 item...