JavaScript: tauira tono

Ki te kore te ruku tonu ki wetereo poto me semantics o te taumahinga JavaScript, ka āwhina i ngā tauira waehere ohie ki te ako hohoro pehea ki te whakapai ake i te auaretanga me te kakama o te whārangi.

JS - reo papatono "i roto i te" pūtirotiro. He whānui wheako mahi ki ngā āhuatanga whārangi, te rongoā taketake i roto i te mara o te hōtaka ahanoa-hāngai JavaScript, ki te kōrero ki te tūmau, e kore hoki tokomaha o ngā tauira waehere JavaScript e wātea ana tonu ki te maramarama e ia faaohipa "taea ko".

General roto tūmataiti: tīmatanga ohie

Papatonotanga i roto i te pūtirotiro ko ngā taitamariki tonu, engari hohoro whakaemi he-kounga tiketike, me te wheako taketake. Ko te wetereo me semantics o te JavaScript riro i parauhia "tupuna", me i wahi te taumahinga me māmā o te wetereo - ake mai i te reo hōtaka mua ipurangi-, rawa C / C ++, Pascal.

Tirotiro ki tauira JavaScript, e kore e rapu i ki matau tonu te arorau o whakaaro o nga kaituhi me te taumahinga o te hātepe - tenei mahi unpromising, pai ki te arotahi ki runga i to koutou ake mahi tūmataiti.

Noa tīmata ki te pūraweke onload hononga i runga i te tūtohu tinana, me te tuhituhi tuku iho te "Hello" i roto i te kāhua hou "I`m rite".

whakaatu ēnei tauira i roto i JavaScript:

• te hui onload, puta i muri i whakaritea whārangi kawenga e te pūnanao - GoPage () mahi;
• e tango i te pikaunga whārangi, me mahi whakahaere GoPage ();
• he mahi mataara tukunga kōrero o te reo, e whakaatu he karere i roto i te pūtirotiro "au ahau rite";
• Te titau Pūtirotiro manuhiri tauhohenga.

whakaahua ana i te kōrero i te mahi e te nuinga o te tikanga kia mahi i muri i te whārangi download, me te tīmata i te matawā.

Tino watea: kua tino tata hono JS ki te huānga whārangi. Na, document.getElementById karanga whakarato te hono ki te Tauoti ki "scTimer" pūtāutu. Mā te whakamahi i te hanga dTimer.innerHTML = "tetahi whaimana waehere HTML", ka taea e hihiri koe te huri i te tirotiro o te Tiwihana.

kia rawa utu te reira i whakarongo ki te hapa i roto i te tinana o te undesirability o hōtuhi i JavaScript. Tauira o tenei meinga hopearaa ino. i tohua e te waehere runga ake mataara ( 'au ahau rite'), me te mahi e kore e te reira. Hei tohu ahua tetahi o nga rarangi whakaaetia apostrophes: e rua kotahi, me te rua, ai roto i te rua o tetahi ahua e whakamahia ai anake, te atu - rite te tohu.

I roto i tenei take kia kua i tohua ai, ahakoa mataara ( "au ahau rite"), mataara ( 'I`m rite'), mataara ( 'ahau \' m rite '), ranei te tahi atu ngā.

Hapa i roto i te JS-waehere

I te tuatahi ko te pūtirotiro, i runga i te kaupapa o te manuhiri utaina ia whārangi o te pae, hanga he rakau DOM ka whakahohe a JavaScript mahi: kia hoatu ki a ia te whai wāhi ki te tātari i te whārangi utaina, arawhiti ona āhuatanga, kawenga hui, ka hono atu ki te hanga whakapā ki te tūmau.

Tātari JavaScript (tauira), ko reira e tika ana ki te whakarongo ki te waehere patuiro. Ko piki taka i runga i te kaiwhakawhanake tenei tukanga. Ko te pūtirotiro i roto i i whakamana i te mahi kei te, kia tono enei atu ranei taputapu patuiro, engari whakaatu wheako e pipiki tino ki te wetereo reo, te noho noa me te tika o te hātepe i te pānga nui nui i runga i te paetae o ngā hua whakahaere.