es6 Two ways to get the first few elements of an array: 1. Use splice() to intercept array fragments to get the first N array elements. The syntax is "array object.splice(0,N)"; 2. . Use slice() to intercept array fragments. The syntax "array object.slice(0,N)" can obtain the first N array elements.
The operating environment of this tutorial: Windows 7 system, ECMAScript version 6, Dell G3 computer.
In es6, you can use the following two methods to intercept an array and get the first few elements of the array
splice()
slice()
1. Use splice() to intercept the array
The splice() method can add elements, delete elements, or Intercept array fragments. When an element is deleted, the deleted array fragment will be returned, so the splice() method can be used to intercept the array fragment.
Example 1: Intercept the first two elements of the array
var fruits = ["Banana", "Orange", "Lemon", "Apple", "Mango"]; console.log(fruits); var citrus = fruits.splice(0,2); console.log("数组前两个元素:"+citrus);
Example 2: Intercept the first three elements of the array
var citrus = fruits.splice(0,3); console.log("数组前3个元素:"+citrus);
2. Use slice() to intercept the array
The slice() method has similar functions to the splice() method, but it can only intercept the elements of the specified section in the array. , and return this subarray. This method contains two parameters, specifying the subscripts of the starting and ending positions of the intercepted subarray.
You only need to set the first parameter to 0 and the second parameter to the specified N digits to get the first N elements of the array.
var fruits = ["Banana", "Orange", "Lemon", "Apple", "Mango"]; console.log(fruits); console.log("数组前1个元素:"+fruits.slice(0,1)); console.log("数组前2个元素:"+fruits.slice(0,2)); console.log("数组前3个元素:"+fruits.slice(0,3));
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