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This article introduces the knowledge of "how to traverse objects and arrays in jquery". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

JS forEach method

Arr [] .forEach (function (value,index,array) {/ / do something})

Parameters: current item in value array, index of current item in index, array raw array

If there are several items in the array, the anonymous callback function passed in needs to be executed several times

In theory, this method does not return a value, it just traverses every item in the array and does not modify the original array, but you can modify the original array through the index of the array.

Var arr = [12Jing 23 index 24jue 42jue 1]; var res = arr.forEach (function (item,index,input) {input [index] = item*10;}) console.log (res); / /-- > undefined;console.log (ary); / /-- > [120Jing 230Jing 240jue 420jue 10]; changed the original array through the array index

JS map method

Arr [] .map (function (value,index,array) {/ / do something})

Parameters: current item in value array, index of current item in index, array raw array

Difference: map's callback function supports the return value of return; what is return is equivalent to changing this item in the array (does not affect the original array, but is equivalent to cloning a copy of the original array and changing the corresponding items in the cloned array)

Var arr = [12Yue23jin24 return item*10; 42L1]; var res = arr.map (function (item,index,input) {return item*10;}) console.log (res); / /-- > [120pcpl 230pcm240pr 420pl]; the original array made a copy and modified console.log (ary); / /-- > [12jie 23jie 24jie 42ji1]; the original array did not change.

JQuery $.each method

$.each (arr, function (index,value) {/ / do something})

Parameters: the array to be traversed by arr, the index of the current item in index, the current item in the value array

The first and second arguments are exactly the opposite of the above two functions. Be careful not to get it wrong.

Var arr = [1225 23 function 24 42 index,item 1]; $.each (arr, function (index,item) {console.log (index) / / 01234 console.log (item) / / 1223 24 421}) this is the end of how to traverse objects and arrays in jquery. Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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